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  <p align="center" style="border:none;margin:0in 0in .0001pt;padding:0in;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">&nbsp;</font></b></p>
  
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  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="5" face="Times New Roman" style="font-size:18.0pt;font-weight:bold;">UNITED
  STATES<br>
  SECURITIES AND EXCHANGE COMMISSION</font></b></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">Washington, DC&#160; 20549</font></b></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <div align="center" style="margin:0in 0in .0001pt;text-align:center;"><hr size="1" width="25%" noshade color="black" align="center"></div>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="5" face="Times New Roman" style="font-size:18.0pt;font-weight:bold;">FORM&nbsp;8-K</font></b></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <div align="center" style="margin:0in 0in .0001pt;text-align:center;"><hr size="1" width="25%" noshade color="black" align="center"></div>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="3" face="Times New Roman" style="font-size:12.0pt;font-weight:bold;">CURRENT
  REPORT</font></b></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="3" face="Times New Roman" style="font-size:12.0pt;font-weight:bold;">Pursuant
  to Section&nbsp;13 or 15(d)&nbsp;of<br>
  the Securities Exchange Act of 1934</font></b></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Date of report (Date of earliest event reported) <b>May&nbsp;6,
  2008 (May&nbsp;6, 2008)</b></font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="5" face="Times New Roman" style="font-size:18.0pt;font-weight:bold;">CORPORATE
  OFFICE PROPERTIES TRUST</font></b><font size="2" style="font-size:10.0pt;"><br>
  (Exact name of registrant as specified in its charter)</font></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <div align="center">
  
  <table border="0" cellspacing="0" cellpadding="0" width="100%" style="border-collapse:collapse;width:100.0%;">
   <tr>
    <td width="32%" valign="top" style="padding:0in .7pt 0in .7pt;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">Maryland</font></b></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:2.0%;">
    <p style="margin:0in 0in .0001pt;"><b><font size="2" face="Times New Roman" style="font-size:1.0pt;font-weight:bold;">&nbsp;</font></b></p>
    </td>
    <td width="32%" valign="top" style="padding:0in .7pt 0in .7pt;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">1-14023</font></b></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:2.0%;">
    <p style="margin:0in 0in .0001pt;"><b><font size="2" face="Times New Roman" style="font-size:1.0pt;font-weight:bold;">&nbsp;</font></b></p>
    </td>
    <td width="32%" valign="top" style="padding:0in .7pt 0in .7pt;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">23-2947217</font></b></p>
    </td>
   </tr>
   <tr>
    <td width="32%" valign="top" style="padding:0in .7pt 0in .7pt;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(State or other jurisdiction of<br>
    incorporation)</font></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:2.0%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="32%" valign="top" style="padding:0in .7pt 0in .7pt;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(Commission<br>
    File Number)</font></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:2.0%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="32%" valign="top" style="padding:0in .7pt 0in .7pt;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(IRS Employer<br>
    Identification Number)</font></p>
    </td>
   </tr>
  </table>
  
  </div>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">6711 Columbia Gateway Drive, Suite&nbsp;300<br>
  Columbia, Maryland 21046</font></b><font size="2" style="font-size:10.0pt;"><br>
  (Address of principal executive offices)</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">(443) 285-5400</font></b><font size="2" style="font-size:10.0pt;"><br>
  (Registrant&#146;s telephone number, including area code)</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Check
  the appropriate box below if the Form&nbsp;8-K filing is intended to
  simultaneously satisfy the filing obligation of the registrant under any of the
  following provisions (see General Instruction A.2 below):</font></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Wingdings" style="font-size:10.0pt;">o</font><font size="2" face="Times New Roman" style="font-size:10.0pt;">
  Written communications pursuant to Rule&nbsp;425 under the Securities Act (17
  CFR 230.425)</font></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Wingdings" style="font-size:10.0pt;">o</font><font size="2" face="Times New Roman" style="font-size:10.0pt;">
  Soliciting material pursuant to Rule&nbsp;14a-12 under the Exchange Act (17 CFR
  240.14a-12)</font></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt 9.0pt;text-indent:-9.0pt;"><font size="2" face="Wingdings" style="font-size:10.0pt;">o</font><font size="2" face="Times New Roman" style="font-size:10.0pt;">
  Pre-commencement communications pursuant to Rule&nbsp;14d-2(b)&nbsp;under the
  Exchange Act (17 CFR 240.14d-2(b))</font></p>
  
  <p style="margin:0in 0in .0001pt 9.0pt;text-indent:-9.0pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt 9.0pt;text-indent:-9.0pt;"><font size="2" face="Wingdings" style="font-size:10.0pt;">o</font><font size="2" face="Times New Roman" style="font-size:10.0pt;">
  Pre-commencement communications pursuant to Rule&nbsp;13e-4(c)&nbsp;under the
  Exchange Act (17 CFR 240.13e-4(c))</font></p>
  
  <p style="margin:0in 0in .0001pt 9.0pt;text-indent:-9.0pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <div style="border:none;border-top:double windowtext 6.0pt;padding:0in 0in 0in 0in;">
  
  <p style="border:none;margin:0in 0in .0001pt 9.0pt;padding:0in;text-indent:-9.0pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  </div>
  
  <div style="margin:0in 0in .0001pt;"><hr size="3" width="100%" noshade color="#010101" align="left"></div>
  
  </div>
  <!-- SEQ.=1,FOLIO='',FILE='C:\JMS\jtaylora\08-13414-1\task2916504\13414-1-ba.htm',USER='jtaylora',CD='May  5 22:43 2008' -->
  
  
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  <div>
  
  <p style="font-weight:bold;margin:0in 0in .0001pt;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></b></p>
  
  <p style="font-weight:bold;margin:0in 0in .0001pt;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;">Item 2.02.&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; Results
  of Operations and Financial Condition</font></b></p>
  
  <p style="font-weight:bold;margin:0in 0in .0001pt;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></b></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;text-indent:.25in;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">In connection with its release of
  earnings on May&nbsp;6, 2008, the Registrant is making available certain
  additional information pertaining to its properties and operations as of and
  for the period ended March&nbsp;31, 2008.&#160;
  This information is furnished herewith as Exhibit&nbsp;99.1 and is
  incorporated herein by reference.</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;text-indent:.25in;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;text-indent:.25in;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">The information included herein,
  including the exhibits, shall not be deemed &#147;filed&#148; for any purpose, including
  the purposes of Section&nbsp;18 of the Securities Exchange Act of 1934, as
  amended (the &#147;Exchange Act&#148;), or subject to liabilities of that Section.&#160; The information included herein, including
  the exhibits, shall also not be deemed incorporated by reference into any
  filing under the Securities Act of 1933, as amended (the &#147;Securities Act&#148;), or
  the Exchange Act regardless of any general incorporation language in such
  filing.</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;text-indent:.25in;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;text-indent:.25in;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">The Registrant uses non-GAAP
  financial measures in earnings press releases and information furnished to the
  Securities and Exchange Commission.&#160; The
  Registrant believes that these measures are helpful to investors in measuring
  its performance and comparing such performance to other real estate investment
  trusts (&#147;REITs&#148;).&#160; Descriptions of these
  measures are set forth below.</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;text-indent:.25in;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><u><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">Funds from operations (&#147;FFO&#148;)</font></u></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Funds
  from operations (&#147;FFO&#148;) is defined as net income computed using GAAP, excluding
  gains (or losses) from sales of real estate, plus real estate-related
  depreciation and amortization after adjustments for unconsolidated partnerships
  and joint ventures.&#160; Gains from the sale
  of real estate that are attributable to sales of non-operating properties are
  included in FFO.&#160; Gains from sales of
  newly-developed properties less accumulated depreciation, if any, required
  under GAAP are also included in FFO on the basis that development services are
  the primary revenue generating activity; the Registrant believes that inclusion
  of these development gains is in accordance with the National Association of
  Real Estate Investment Trusts&#146; (&#147;NAREIT&#148;) definition of FFO, although others
  may interpret the definition differently.</font></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">Accounting for real estate assets using historical cost
  accounting under GAAP assumes that the value of real estate assets diminishes
  predictably over time.&#160; NAREIT stated in
  its April&nbsp;2002 White Paper on Funds from Operations that &#147;since real
  estate asset values have historically risen or fallen with market conditions,
  many industry investors have considered presentations of operating results for
  real estate companies that use historical cost accounting to be insufficient by
  themselves.&#148;&#160; As a result, the concept of
  FFO was created by NAREIT for the REIT industry to &#147;address this problem.&#148;&#160; The Registrant agrees with the concept of FFO
  and believes that FFO is useful to management and investors as a supplemental
  measure of operating performance because, by excluding gains and losses related
  to sales of previously depreciated operating real estate properties and
  excluding real estate-related depreciation and amortization, FFO can help one
  compare the Registrant&#146;s operating performance between periods.&#160; In addition, since most equity REITs provide
  FFO information to the investment community, the Registrant believes that FFO
  is useful to investors as a supplemental measure for comparing its results to
  those of other equity REITs. The Registrant believes that net income is the
  most directly comparable GAAP measure to FFO.</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">Since FFO excludes certain items
  includable in net income, reliance on the measure has limitations; management
  compensates for these limitations by using the measure simply as a supplemental
  measure that is weighed in the balance with other GAAP and non-GAAP
  measures.&#160; </font></p>
  
  <p align="center" style="color:black;margin:0in 0in .0001pt;text-align:center;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="center" style="color:black;margin:0in 0in .0001pt;text-align:center;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">2</font></p>
  
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  </div>
  <!-- SEQ.=1,FOLIO='2',FILE='C:\JMS\jtaylora\08-13414-1\task2916504\13414-1-ba.htm',USER='jtaylora',CD='May  5 22:43 2008' -->
  
  
  <br clear="all" style="page-break-before:always;">
  
  
  <div>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">FFO is not necessarily an
  indication of the Registrant&#146;s cash flow available to fund cash needs.&#160; Additionally, it should not be used as an
  alternative to net income when evaluating the Registrant&#146;s financial
  performance or to cash flow from operating, investing and financing activities
  when evaluating the Registrant&#146;s liquidity or ability to make cash
  distributions or pay debt service.&#160; The
  FFO presented by the Registrant may not be comparable to the FFO presented by
  other REITs since they may interpret the current NAREIT definition of FFO
  differently or they may not use the current NAREIT definition of FFO.</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><u><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">Funds from operations-Basic (&#147;Basic FFO&#148;)</font></u></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">Basic FFO is FFO adjusted to (1)&nbsp;subtract (a)&nbsp;preferred
  share dividends and (b)&nbsp;issuance costs associated with redeemed preferred
  shares and (2)&nbsp;add back GAAP net income allocated to common units in
  Corporate Office Properties, L.P. (the &#147;Operating Partnership&#148;) not owned by
  the Registrant.&#160; With these adjustments,
  Basic FFO represents FFO available to common shareholders and common
  unitholders.&#160; Common units in the
  Operating Partnership are substantially similar to common shares of beneficial
  interest in the Registrant (&#147;common shares&#148;); common units in the Operating
  Partnership are also exchangeable into common shares, subject to certain
  conditions.&#160; The Registrant believes that
  Basic FFO is useful to investors due to the close correlation of common units
  to common shares.&#160; The Registrant
  believes that net income is the most directly comparable GAAP measure to Basic
  FFO. Basic FFO has essentially the same
  limitations as FFO; management compensates for these limitations in essentially
  the same manner as described above for FFO.</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><u><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">FFO per diluted share (&#147;Diluted FFO per share&#148;)</font></u></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">Diluted FFO per share is (1)&nbsp;Basic FFO adjusted to add
  back any convertible preferred share dividends and any other changes in Basic
  FFO that would result from the assumed conversion of securities that are
  convertible or exchangeable into common shares divided by (2)&nbsp;the sum of
  the (a)&nbsp;weighted average common shares outstanding during a period, (b)&nbsp;weighted
  average common units outstanding during a period and (c)&nbsp;weighted average
  number of potential additional common shares that would have been outstanding
  during a period if other securities that are convertible or exchangeable into
  common shares were converted or exchanged.&#160;
  However, the computation of Diluted FFO per share does not assume
  conversion of securities that are convertible into common shares if the
  conversion of those securities would increase Diluted FFO per share in a given
  period.&#160; The Registrant believes that
  Diluted FFO per share is useful to investors because it provides investors with
  a further context for evaluating its FFO results in the same manner that
  investors use earnings per share in evaluating net income available to common
  shareholders.&#160; In addition, since most
  equity REITs provide Diluted FFO per share information to the investment
  community, the Registrant believes Diluted FFO per share is a useful
  supplemental measure for comparing the Registrant to other equity REITs.&#160; The Registrant believes that diluted EPS is
  the most directly comparable GAAP measure to Diluted FFO per share.&#160; Diluted FFO per share has most of the same limitations as Diluted FFO (described
  below); management compensates for these limitations in essentially the same
  manner as described below for Diluted&nbsp;FFO.</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><u><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">Funds from operations-diluted (&#147;Diluted FFO&#148;)</font></u></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">Diluted FFO is Basic FFO adjusted to add back any convertible
  preferred share dividends and any other changes in Basic FFO that would result from
  the assumed conversion of securities that are convertible or exchangeable into
  common shares.&#160; However, the computation
  of Diluted FFO does not assume conversion of securities that are convertible
  into common shares if the conversion of those securities would increase Diluted
  FFO per share in a given period.&#160; The
  Registrant believes that Diluted FFO is useful to investors because it is the
  numerator used to compute Diluted FFO per share.&#160; In addition, since most equity REITs provide
  Diluted&nbsp;FFO</font></p>
  
  <p align="center" style="color:black;margin:0in 0in .0001pt;text-align:center;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="center" style="color:black;margin:0in 0in .0001pt;text-align:center;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">3</font></p>
  
  <div align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><hr size="3" width="100%" noshade color="#010101" align="left"></div>
  
  </div>
  <!-- SEQ.=1,FOLIO='3',FILE='C:\JMS\jtaylora\08-13414-1\task2916504\13414-1-ba.htm',USER='jtaylora',CD='May  5 22:43 2008' -->
  
  
  <br clear="all" style="page-break-before:always;">
  
  
  <div>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">information to the investment community, the Registrant
  believes Diluted FFO is a useful supplemental measure for comparing the
  Registrant to other equity REITs.&#160; The
  Registrant believes that the numerator to diluted EPS is the most directly
  comparable GAAP measure to Diluted FFO.&#160; Since Diluted FFO excludes certain items
  includable in the numerator to diluted EPS, reliance on the measure has
  limitations; management compensates for these limitations by using the measure
  simply as a supplemental measure that is weighed in the balance with other GAAP
  and non-GAAP measures.&#160; Diluted FFO is
  not necessarily an indication of the Registrant&#146;s cash flow available to fund
  cash needs.&#160; Additionally, it should not
  be used as an alternative to net income when evaluating the Registrant&#146;s
  financial performance or to cash flow from operating, investing and financing
  activities when evaluating the Registrant&#146;s liquidity or ability to make cash
  distributions or pay debt service.&#160; The
  Diluted FFO presented by the Registrant may not be comparable to the Diluted
  FFO presented by other REITs.</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><u><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">Adjusted funds from operations-diluted (&#147;Diluted AFFO&#148;)</font></u></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">Diluted AFFO is Diluted FFO adjusted
  for the following: (1)&nbsp;the elimination of the effect of (a)&nbsp;noncash
  rental revenues (comprised of straight-line rental adjustments, which includes
  the amortization of recurring tenant incentives, and amortization of deferred
  market rental revenue, both of which are described under &#147;Cash NOI&#148; below) and (b)&nbsp;accounting
  charges for original issuance costs associated with redeemed preferred shares;
  and (2)&nbsp;recurring capital expenditures (defined below).&#160; The Registrant believes that Diluted AFFO is
  an important supplemental measure of liquidity for an equity REIT because it
  provides management and investors with an indication of its ability to incur
  and service debt and to fund dividends and other cash needs.&#160; In addition, since most equity REITs provide
  Diluted AFFO information to the investment community, the Registrant believes
  that Diluted AFFO is a useful supplemental measure for comparing the Registrant
  to other equity REITs.&#160; The Registrant
  believes that the numerator to diluted EPS is the most directly comparable GAAP
  measure to Diluted AFFO.&#160; Since Diluted AFFO excludes certain items
  includable in the numerator to diluted EPS, reliance on the measure has
  limitations; management compensates for these limitations by using the measure
  simply as a supplemental measure that is weighed in the balance with other GAAP
  and non-GAAP measures.&#160; In addition, see
  the discussion below regarding the limitations of recurring capital
  expenditures, which is used to derive Diluted AFFO.&#160; Diluted AFFO is not necessarily an indication
  of the Registrant&#146;s cash flow available to fund cash needs.&#160; Additionally, it should not be used as an
  alternative to net income when evaluating the Registrant&#146;s financial
  performance or to cash flow from operating, investing and financing activities
  when evaluating the Registrant&#146;s liquidity or ability to make cash
  distributions or pay debt service.&#160; The
  Diluted AFFO presented by the Registrant may not be comparable to similar
  measures presented by other equity REITs.</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><u><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">Recurring capital expenditures</font></u></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">Recurring capital expenditures are defined as capital
  expenditures, tenant improvements and incentives and leasing costs associated
  with operating properties that are not (1)&nbsp;items contemplated prior to the
  acquisition of a property, (2)&nbsp;improvements associated with the expansion
  of a building or its improvements, (3)&nbsp;renovations to a building which
  change the underlying classification of the building (for example, from
  industrial to office or Class&nbsp;C office to Class&nbsp;B office) or (4)&nbsp;capital
  improvements that represent the addition of something new to the property
  rather than the replacement of something (for example, the addition of a new
  heating and air conditioning unit that is not replacing one that was previously
  there).&#160; The Registrant believes that
  recurring capital expenditures is an important measure of performance for a
  REIT because it provides a measure of the capital expenditures that the
  Registrant can expect to incur on an ongoing basis, which is significant to how
  the Registrant manages its business since these expenditures are funded using cash
  flow from operations.&#160; As a result, the
  measure provides a further indication of the cash flow from operations that is
  available to fund other uses.&#160; The </font></p>
  
  <p align="center" style="color:black;margin:0in 0in .0001pt;text-align:center;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="center" style="color:black;margin:0in 0in .0001pt;text-align:center;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">4</font></p>
  
  <div align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><hr size="3" width="100%" noshade color="#010101" align="left"></div>
  
  </div>
  <!-- SEQ.=1,FOLIO='4',FILE='C:\JMS\jtaylora\08-13414-1\task2916504\13414-1-ba.htm',USER='jtaylora',CD='May  5 22:43 2008' -->
  
  
  <br clear="all" style="page-break-before:always;">
  
  
  <div>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">Registrant believes that tenant improvements and incentives,
  capital improvements and leasing costs associated with operating properties are
  the most directly comparable GAAP measures.&#160;
  Recurring capital expenditures do not reflect all capital expenditures
  incurred by the Registrant for the periods reported; the Registrant compensates
  for this limitation by also using the comparable GAAP measure.&#160; The recurring
  capital expenditures presented by the
  Registrant may not be comparable to the recurring capital expenditures
  presented by other REITs.</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><u><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">Combined real estate revenue</font></u></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">Combined real estate revenue is total revenue from real
  estate operations, including rental revenue and tenant recoveries and other
  revenue, including discontinued operations.&#160;
  The Registrant uses this measure to evaluate the revenue produced by its
  real estate properties, including those reported in discontinued operations.
  The Registrant believes that total revenue is the most directly comparable GAAP
  measure to combined real estate revenue.&#160;
  Combined real estate revenue excludes other types of revenue earned by
  the Registrant, including construction contract and other service operations
  revenues. The measure also includes discontinued operations and, by doing so,
  does not reflect the overall operating performance of the Registrant&#146;s
  continuing operations.&#160; Management compensates for these limitations by
  evaluating this measure in conjunction with the most directly comparable
  GAAP measure and other operating statistics involving revenue.</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><u><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">Combined net operating income (&#147;Combined NOI&#148;)</font></u></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">Combined NOI is combined real estate revenue reduced by total
  property expenses associated with real estate operations, including
  discontinued operations; total property expenses, as used in this definition,
  do not include depreciation, amortization or interest expense associated with
  real estate operations.&#160; The Registrant
  believes that Combined NOI is an important supplemental measure of operating
  performance for a REIT&#146;s operating real estate because it provides a measure of
  the core real estate operations, rather than factoring in depreciation and
  amortization or corporate financing and general and administrative expenses;
  this measure is particularly useful in the opinion of the Registrant in
  evaluating the performance of geographic segments, same-office property
  groupings and individual properties.&#160; The
  Registrant believes that net income is the most directly comparable GAAP
  measure to Combined NOI.&#160; The measure
  excludes many items that are includable in net income; management compensates for this limitation by using the measure simply as
  a supplemental measure that is weighed in the balance with other GAAP and
  non-GAAP measures.&#160; It should not be used as an alternative to net
  income when evaluating the Registrant&#146;s financial performance or to cash flow
  from operating, investing and financing activities when evaluating the
  Registrant&#146;s liquidity or ability to make cash distributions or pay debt
  service.&#160; Combined NOI presented
  by the Registrant may not be comparable to Combined NOI presented by other equity
  REITs that define the measure differently.</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><u><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">Cash net operating income (&#147;Cash NOI&#148;)</font></u></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">Cash NOI is Combined NOI (defined above) adjusted to
  eliminate the effects of noncash rental revenues (comprised of straight-line
  rental adjustments, which includes the amortization of recurring tenant
  incentives, and amortization of deferred market rental revenue).&#160; Under GAAP, rental revenue is recognized
  evenly over the term of tenant leases.&#160;
  Many leases provide for contractual rent increases and the effect of
  accounting under GAAP for such leases is to accelerate the recognition of lease
  revenue.&#160; Since some leases provide for
  periods under the lease in which rental concessions are provided to tenants,
  the effect of accounting under GAAP is to allocate rental revenue to such
  periods.&#160; Also under GAAP, when a
  property is acquired, in-place operating leases carrying rents above or below
  market are valued as of the date of the acquisition; such value is then
  amortized into rental revenue over the lives of the related leases.</font></p>
  
  <p align="center" style="color:black;margin:0in 0in .0001pt;text-align:center;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="center" style="color:black;margin:0in 0in .0001pt;text-align:center;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">5</font></p>
  
  <div align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><hr size="3" width="100%" noshade color="#010101" align="left"></div>
  
  </div>
  <!-- SEQ.=1,FOLIO='5',FILE='C:\JMS\jtaylora\08-13414-1\task2916504\13414-1-ba.htm',USER='jtaylora',CD='May  5 22:43 2008' -->
  
  
  <br clear="all" style="page-break-before:always;">
  
  
  <div>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">The Registrant believes that Cash NOI is an important
  supplemental measure of operating performance for a REIT&#146;s operating real
  estate because it makes adjustments to Combined NOI for revenue that is not
  associated with cash to the Registrant.&#160;
  As is the case with Combined NOI, the measure is useful in the opinion
  of the Registrant in evaluating and comparing the performance of geographic
  segments, same-office property groupings and individual properties, although,
  since it adjusts for noncash items, it provides management and investors with a
  further indication of the Registrant&#146;s ability to incur and service debt and to
  fund dividends and other cash needs.&#160; The
  Registrant believes that net income is the most directly comparable GAAP
  measure to Cash NOI.&#160; The measure
  excludes many items that are includable in net income; management compensates for this limitation by using the measure simply as
  a supplemental measure that is weighed in the balance with other GAAP and
  non-GAAP measures.&#160; It should not be used as an alternative to net
  income when evaluating the Registrant&#146;s financial performance or to cash flow
  from operating, investing and financing activities when evaluating the
  Registrant&#146;s liquidity or ability to make cash distributions or pay debt
  service.&#160; The Cash NOI that the
  Registrant presents may not be comparable to similar measures presented by
  other equity REITs.</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><u><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">Cash NOI adjusted for lease termination fees</font></u></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">This measure is Cash NOI (defined above) adjusted to
  eliminate the effects of lease termination fees paid by tenants to terminate
  their lease obligations prior to the end of the agreed lease terms.&#160; Lease termination fees are often recognized
  as revenue in large one-time lump sum amounts upon the termination of tenant
  leases.&#160; The Registrant believes that
  Cash NOI adjusted for lease termination fees is a useful supplemental measure
  of operating performance in evaluating same-office property groupings because
  it provides a means of evaluating the effect that lease terminations had on the
  performance of the property groupings.&#160;
  As in the case of Cash NOI, since the measure adjusts for noncash items,
  it also provides management and investors with a further indication of the
  Registrant&#146;s ability to incur and service debt and to fund dividends and other
  cash needs.&#160; The Registrant believes that
  net income is the most directly comparable GAAP measure to Cash NOI adjusted
  for termination fees.&#160; The measure has essentially the same limitations as Cash
  NOI as well as the further limitation of not reflecting the effect of
  lease termination fees in accordance with GAAP.&#160; Management compensates for these
  limitations by using the measure simply as a supplemental measure that is
  weighed in the balance with other GAAP and non-GAAP measures.</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="left" style="color:black;margin:0in 0in .0001pt;text-align:left;"><u><font size="2" color="black" face="Times New Roman" style="color:windowtext;font-size:10.0pt;">Earnings Before Interest, Income Taxes, Depreciation and
  Amortization (&#147;EBITDA&#148;)</font></u></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">EBITDA
  is net income adjusted for the effects of interest expense, depreciation and
  amortization, income taxes and minority interests.&#160; The Registrant believes that EBITDA is an
  important measure of performance for a REIT because it provides a further tool
  to evaluate the Registrant&#146;s ability to incur and service debt and to fund dividends
  and other cash needs that supplements the previously described non-GAAP
  measures and to compare the Registrant&#146;s operating performance with that of
  other companies.&#160; The Registrant believes
  that net income is the most directly comparable GAAP measure to EBITDA.&#160; EBITDA excludes items that are included in
  net income, including some that require cash outlays; management compensates
  for this limitation by using the measure simply as a supplemental measure that
  is weighed in the balance with other GAAP and non-GAAP measures.&#160;&#160; It should not be used as an alternative to
  net income when evaluating the Registrant&#146;s financial performance or to cash
  flow from operating, investing and financing activities when evaluating the
  Registrant&#146;s liquidity or ability to make cash distributions or pay debt
  service.&#160; Additionally, EBITDA as
  reported by the Registrant may not be comparable to EBITDA reported by other
  equity REITs.</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">6</font></p>
  
  <div style="margin:0in 0in .0001pt;"><hr size="3" width="100%" noshade color="#010101" align="left"></div>
  
  </div>
  <!-- SEQ.=1,FOLIO='6',FILE='C:\JMS\jtaylora\08-13414-1\task2916504\13414-1-ba.htm',USER='jtaylora',CD='May  5 22:43 2008' -->
  
  
  <br clear="all" style="page-break-before:always;">
  
  
  <div>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;"><u><font size="2" face="Times New Roman" style="font-size:10.0pt;">Interest
  Coverage Ratio-Combined NOI and Interest Coverage Ratio-EBITDA</font></u></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">These
  measures divide either combined NOI or EBITDA by interest expense on continuing
  and discontinued operations.&#160; The
  Registrant believes that these ratios are useful measures in evaluating the
  relationship of earnings to the total cash flow requirements for interest on
  loans associated with operating properties and, as such, are important tools in
  the Registrant&#146;s finance policy management.</font></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;"><u><font size="2" face="Times New Roman" style="font-size:10.0pt;">Debt
  Service Coverage Ratio-Combined NOI and Debt Service Coverage Ratio-EBITDA</font></u></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">These
  measures divide either combined NOI or EBITDA by the sum of interest expense on
  continuing and discontinued operations and scheduled principal amortization on
  mortgage loans for continuing and discontinued operations.&#160; The Registrant believes that these ratios are
  useful measures in evaluating the relationship of earnings to the total cash
  flow requirements of loans associated with operating properties and, as such,
  are important tools in the Registrant&#146;s finance policy management.</font></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;"><u><font size="2" face="Times New Roman" style="font-size:10.0pt;">Fixed
  Charge Coverage Ratio-Combined NOI and Fixed Charge Coverage Ratio-EBITDA</font></u></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">These
  measures divide either combined NOI or EBITDA by the sum of (1)&nbsp;interest
  expense on continuing and discontinued operations, (2)&nbsp;dividends on
  preferred shares and (3)&nbsp;distributions on preferred units in the Operating
  Partnership not owned by the Registrant.&#160;
  The Registrant believes that these ratios are useful measures in
  evaluating the relationship of earnings to the cash flow requirements of (1)&nbsp;interest
  expense on loans associated with operating properties and (2)&nbsp;dividends to
  preferred equity holders and, as such, are important tools in the Registrant&#146;s
  finance policy management.</font></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;"><u><font size="2" face="Times New Roman" style="font-size:10.0pt;">Combined
  NOI as a Percentage of Combined Real Estate Revenues and EBITDA as a Percentage
  of Combined Real Estate Revenues</font></u></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">These
  measures divide either Combined NOI or EBITDA by total real estate revenues
  from continuing and discontinued operations.&#160;
  The Registrant believes that net income divided by combined real estate
  revenue is the most directly comparable GAAP measure to these two measures.</font></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;"><u><font size="2" face="Times New Roman" style="font-size:10.0pt;">General
  and Administrative Expenses as a Percentage of Combined Real Estate Revenue or
  EBITDA</font></u></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">These
  measures divide general and administrative expenses by either Combined Real
  Estate Revenue or EBITDA.&#160; The Registrant
  believes that general and administrative expenses divided by net income is the
  most directly comparable GAAP measure.</font></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;"><u><font size="2" face="Times New Roman" style="font-size:10.0pt;">Recurring
  Capital Expenditures as a Percentage of Combined NOI</font></u></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">This
  measure divides recurring capital expenditures by NOI.</font></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;"><u><font size="2" face="Times New Roman" style="font-size:10.0pt;">FFO
  Diluted Payout Ratio and AFFO Diluted Payout Ratio</font></u></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">These
  measures are defined as (1)&nbsp;the sum of (A)&nbsp;dividends on common shares
  and (B)&nbsp;dividends on common and convertible preferred shares and
  distributions to holders of interests in the Operating Partnership when such
  dividends and distributions are included in Diluted FFO and Diluted AFFO
  divided by (2)&nbsp;either Diluted FFO or Diluted AFFO.&#160; The Registrant believes that these ratios are
  useful to investors as supplemental measures of its ability to make
  distributions to investors.&#160; In addition,
  since most equity REITs provide these ratios, the Registrant believes they are
  useful supplemental measures for comparing the Registrant to other equity
  REITs.&#160; The Registrant believes that Earnings
  Payout Ratio is the most comparable GAAP measure.&#160; Earnings Payout Ratio is defined as dividends
  on common shares divided by net income available to common shareholders.&#160; Since FFO Diluted Payout Ratio and AFFO
  Diluted Payout Ratio are derived from Diluted FFO and Diluted AFFO, they share
  the limitations previously discussed for </font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">7</font></p>
  
  <div style="margin:0in 0in .0001pt;"><hr size="3" width="100%" noshade color="#010101" align="left"></div>
  
  </div>
  <!-- SEQ.=1,FOLIO='7',FILE='C:\JMS\jtaylora\08-13414-1\task2916504\13414-1-ba.htm',USER='jtaylora',CD='May  5 22:43 2008' -->
  
  
  <br clear="all" style="page-break-before:always;">
  
  
  <div>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">those
  measures; management compensates for these limitations by using the measures
  simply as supplemental measures that are weighed in the balance with other GAAP
  and non-GAAP measures.</font></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;"><u><font size="2" face="Times New Roman" style="font-size:10.0pt;">Dividend
  Coverage-FFO Diluted and Dividend Coverage-AFFO Diluted</font></u></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">These
  measures divide either Diluted FFO or Diluted AFFO by the sum of (1)&nbsp;dividends
  on common shares and (2)&nbsp;dividends on common and convertible preferred
  shares and distributions to holders of interests in the Operating Partnership
  when such dividends and distributions are included in Diluted FFO and Diluted
  AFFO.</font></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;"><u><font size="2" face="Times New Roman" style="font-size:10.0pt;">Debt
  to Undepreciated Book Value of Real Estate Assets</font></u></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">This
  measure is defined as mortgage loans payable divided by net investment in real
  estate presented on the Registrant&#146;s consolidated balance sheet excluding the
  effect of accumulated depreciation incurred to date on such real estate.&#160; The Registrant believes that the measure of
  Debt to Undepreciated Real Estate Assets is useful to management and investors
  as a supplemental measure of its borrowing levels.&#160; In addition, since most equity REITs provide
  Debt to Undepreciated Real Estate Asset information, the Registrant believes
  Debt to Undepreciated Real Estate Assets is a useful supplemental measure for
  comparing the Registrant to other equity REITs.&#160;
  The Registrant believes that the measure of Debt to Total Assets,
  defined as mortgage loans payable divided by total assets, is the most comparable
  GAAP measure.&#160; Debt to Undepreciated Real
  Estate Assets excludes the effect of accumulated depreciation, other assets and
  other liabilities; management compensates for these limitations by using the
  measure simply as a supplemental measure that is weighed with the comparable
  GAAP measure and other GAAP and non-GAAP measures.</font></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">Item 9.01.&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; Financial
  Statements and Exhibits</font></b></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <table border="0" cellspacing="0" cellpadding="0" width="100%" style="border-collapse:collapse;width:100.0%;">
   <tr>
    <td width="5%" valign="top" style="padding:0in .7pt 0in .7pt;width:5.7%;">
    <h4 style="font-weight:normal;margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(a)</font></h4>
    </td>
    <td width="94%" valign="top" style="padding:0in .7pt 0in .7pt;width:94.3%;">
    <h4 style="font-weight:normal;margin:0in .3in .0001pt 0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Financial
    Statements of Businesses Acquired</font></h4>
    </td>
   </tr>
   <tr>
    <td width="5%" valign="top" style="padding:0in .7pt 0in .7pt;width:5.7%;">
    <h4 style="font-weight:normal;margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></h4>
    </td>
    <td width="94%" valign="top" style="padding:0in .7pt 0in .7pt;width:94.3%;">
    <h4 style="font-weight:normal;margin:0in .3in .0001pt 0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></h4>
    </td>
   </tr>
   <tr>
    <td width="5%" valign="top" style="padding:0in .7pt 0in .7pt;width:5.7%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="94%" valign="top" style="padding:0in .7pt 0in .7pt;width:94.3%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">None</font></p>
    </td>
   </tr>
   <tr>
    <td width="5%" valign="top" style="padding:0in .7pt 0in .7pt;width:5.7%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
    <td width="94%" valign="top" style="padding:0in .7pt 0in .7pt;width:94.3%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
   </tr>
   <tr>
    <td width="5%" valign="top" style="padding:0in .7pt 0in .7pt;width:5.7%;">
    <h4 style="font-weight:normal;margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(b)</font></h4>
    </td>
    <td width="94%" valign="top" style="padding:0in .7pt 0in .7pt;width:94.3%;">
    <h4 style="font-weight:normal;margin:0in .3in .0001pt 0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Pro
    Forma Financial Information</font></h4>
    </td>
   </tr>
   <tr>
    <td width="5%" valign="top" style="padding:0in .7pt 0in .7pt;width:5.7%;">
    <h4 style="font-weight:normal;margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></h4>
    </td>
    <td width="94%" valign="top" style="padding:0in .7pt 0in .7pt;width:94.3%;">
    <h4 style="font-weight:normal;margin:0in .3in .0001pt 0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></h4>
    </td>
   </tr>
   <tr>
    <td width="5%" valign="top" style="padding:0in .7pt 0in .7pt;width:5.7%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="94%" valign="top" style="padding:0in .7pt 0in .7pt;width:94.3%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">None</font></p>
    </td>
   </tr>
   <tr>
    <td width="5%" valign="top" style="padding:0in .7pt 0in .7pt;width:5.7%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
    <td width="94%" valign="top" style="padding:0in .7pt 0in .7pt;width:94.3%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
   </tr>
   <tr>
    <td width="5%" valign="top" style="padding:0in .7pt 0in .7pt;width:5.7%;">
    <h4 style="font-weight:normal;margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(c)</font></h4>
    </td>
    <td width="94%" valign="top" style="padding:0in .7pt 0in .7pt;width:94.3%;">
    <h4 style="font-weight:normal;margin:0in .3in .0001pt 0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Shell
    Company Transactions</font></h4>
    </td>
   </tr>
   <tr>
    <td width="5%" valign="top" style="padding:0in .7pt 0in .7pt;width:5.7%;">
    <h4 style="font-weight:normal;margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></h4>
    </td>
    <td width="94%" valign="top" style="padding:0in .7pt 0in .7pt;width:94.3%;">
    <h4 style="font-weight:normal;margin:0in .3in .0001pt 0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></h4>
    </td>
   </tr>
   <tr>
    <td width="5%" valign="top" style="padding:0in .7pt 0in .7pt;width:5.7%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="94%" valign="top" style="padding:0in .7pt 0in .7pt;width:94.3%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">None</font></p>
    </td>
   </tr>
   <tr>
    <td width="5%" valign="top" style="padding:0in .7pt 0in .7pt;width:5.7%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
    <td width="94%" valign="top" style="padding:0in .7pt 0in .7pt;width:94.3%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
   </tr>
   <tr>
    <td width="5%" valign="top" style="padding:0in .7pt 0in .7pt;width:5.7%;">
    <h4 style="font-weight:normal;margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(d)</font></h4>
    </td>
    <td width="94%" valign="top" style="padding:0in .7pt 0in .7pt;width:94.3%;">
    <h4 style="font-weight:normal;margin:0in .3in .0001pt 0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Exhibits</font></h4>
    </td>
   </tr>
  </table>
  
  <h4 style="font-weight:normal;margin:0in .3in .0001pt .5in;text-indent:-.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></h4>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <table border="0" cellspacing="0" cellpadding="0" width="100%" style="border-collapse:collapse;width:100.0%;">
   <tr>
    <td width="11%" valign="bottom" style="border:none;border-bottom:solid windowtext 1.0pt;padding:0in .7pt 0in .7pt;width:11.1%;">
    <p style="margin:0in 0in .0001pt;page-break-after:avoid;"><b><font size="1" face="Times New Roman" style="font-size:8.0pt;font-weight:bold;">Exhibit&nbsp;Number</font></b></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:2.9%;">
    <p align="center" style="margin:0in 0in .0001pt;page-break-after:avoid;text-align:center;"><b><font size="1" face="Times New Roman" style="font-size:1.0pt;font-weight:bold;">&nbsp;</font></b></p>
    </td>
    <td width="86%" valign="bottom" style="border:none;border-bottom:solid windowtext 1.0pt;padding:0in .7pt 0in .7pt;width:86.0%;">
    <p align="center" style="margin:0in 0in .0001pt;page-break-after:avoid;text-align:center;"><b><font size="1" face="Times New Roman" style="font-size:8.0pt;font-weight:bold;">Description</font></b></p>
    </td>
   </tr>
   <tr>
    <td width="11%" valign="top" style="border:none;padding:0in .7pt 0in .7pt;width:11.1%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:2.9%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
    <td width="86%" valign="top" style="border:none;padding:0in .7pt 0in .7pt;width:86.0%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
   </tr>
   <tr>
    <td width="11%" valign="top" style="padding:0in .7pt 0in .7pt;width:11.1%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">99.1</font></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:2.9%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="86%" valign="top" style="padding:0in .7pt 0in .7pt;width:86.0%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Supplemental
    information dated March&nbsp;31, 2008 for Corporate Office Properties Trust.</font></p>
    </td>
   </tr>
  </table>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">8</font></p>
  
  <div style="margin:0in 0in 12.0pt;text-indent:0in;"><hr size="3" width="100%" noshade color="#010101" align="left"></div>
  
  </div>
  <!-- SEQ.=1,FOLIO='8',FILE='C:\JMS\jtaylora\08-13414-1\task2916504\13414-1-ba.htm',USER='jtaylora',CD='May  5 22:43 2008' -->
  
  
  <br clear="all" style="page-break-before:always;">
  
  
  <div>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">SIGNATURES</font></b></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;text-indent:.25in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Pursuant to the
  requirements of the Securities Exchange Act of 1934, the Registrant has duly
  caused this Report to be signed on its behalf by the undersigned hereunto duly
  authorized.</font></p>
  
  <p style="margin:0in 0in .0001pt;text-indent:.25in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Dated: May&nbsp;6, 2008</font></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <table border="0" cellspacing="0" cellpadding="0" width="100%" style="border-collapse:collapse;width:100.0%;">
   <tr>
    <td width="50%" valign="top" style="padding:0in .7pt 0in .7pt;width:50.84%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="49%" colspan="3" valign="top" style="padding:0in .7pt 0in .7pt;width:49.16%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">CORPORATE OFFICE PROPERTIES TRUST</font></p>
    </td>
   </tr>
   <tr>
    <td width="50%" valign="top" style="padding:0in .7pt 0in .7pt;width:50.84%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
    <td width="49%" colspan="3" valign="top" style="padding:0in .7pt 0in .7pt;width:49.16%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
   </tr>
   <tr>
    <td width="50%" valign="top" style="padding:0in .7pt 0in .7pt;width:50.84%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="6%" colspan="2" valign="top" style="padding:0in .7pt 0in .7pt;width:6.06%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">By:</font></p>
    </td>
    <td width="43%" valign="top" style="border:none;border-bottom:solid windowtext 1.0pt;padding:0in .7pt 0in .7pt;width:43.1%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">/s/ Randall M. Griffin</font></p>
    </td>
   </tr>
   <tr>
    <td width="50%" valign="top" style="padding:0in .7pt 0in .7pt;width:50.84%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="6%" colspan="2" valign="top" style="padding:0in .7pt 0in .7pt;width:6.06%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Name:</font></p>
    </td>
    <td width="43%" valign="top" style="padding:0in .7pt 0in .7pt;width:43.1%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Randall M. Griffin</font></p>
    </td>
   </tr>
   <tr>
    <td width="50%" valign="top" style="padding:0in .7pt 0in .7pt;width:50.84%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="6%" colspan="2" valign="top" style="padding:0in .7pt 0in .7pt;width:6.06%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Title:</font></p>
    </td>
    <td width="43%" valign="top" style="padding:0in .7pt 0in .7pt;width:43.1%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">President and Chief Executive Officer</font></p>
    </td>
   </tr>
   <tr>
    <td width="50%" valign="top" style="padding:0in .7pt 0in .7pt;width:50.84%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
    <td width="49%" colspan="3" valign="top" style="padding:0in .7pt 0in .7pt;width:49.16%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
   </tr>
   <tr>
    <td width="50%" valign="top" style="padding:0in .7pt 0in .7pt;width:50.84%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
    <td width="49%" colspan="3" valign="top" style="padding:0in .7pt 0in .7pt;width:49.16%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
   </tr>
   <tr>
    <td width="50%" valign="top" style="padding:0in .7pt 0in .7pt;width:50.84%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="5%" valign="top" style="padding:0in .7pt 0in .7pt;width:5.98%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">By:</font></p>
    </td>
    <td width="43%" colspan="2" valign="top" style="border:none;border-bottom:solid windowtext 1.0pt;padding:0in .7pt 0in .7pt;width:43.18%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">/s/ Stephen E. Riffee</font></p>
    </td>
   </tr>
   <tr>
    <td width="50%" valign="top" style="padding:0in .7pt 0in .7pt;width:50.84%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="5%" valign="top" style="padding:0in .7pt 0in .7pt;width:5.98%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Name:</font></p>
    </td>
    <td width="43%" colspan="2" valign="top" style="padding:0in .7pt 0in .7pt;width:43.18%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Stephen E. Riffee</font></p>
    </td>
   </tr>
   <tr>
    <td width="50%" valign="top" style="padding:0in .7pt 0in .7pt;width:50.84%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="5%" valign="top" style="padding:0in .7pt 0in .7pt;width:5.98%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Title:</font></p>
    </td>
    <td width="43%" colspan="2" valign="top" style="padding:0in .7pt 0in .7pt;width:43.18%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Executive Vice President
    and</font></p>
    </td>
   </tr>
   <tr>
    <td width="50%" valign="top" style="padding:0in .7pt 0in .7pt;width:50.84%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="5%" valign="top" style="padding:0in .7pt 0in .7pt;width:5.98%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="43%" colspan="2" valign="top" style="padding:0in .7pt 0in .7pt;width:43.18%;">
    <p style="margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Chief Financial Officer</font></p>
    </td>
   </tr>
   <tr height="0">
    <td width="380" style="border:none;"></td>
    <td width="45" style="border:none;"></td>
    <td width="1" style="border:none;"></td>
    <td width="322" style="border:none;"></td>
   </tr>
  </table>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">9</font></p>
  
  <div style="margin:0in 0in .0001pt;text-indent:0in;"><hr size="3" width="100%" noshade color="#010101" align="left"></div>
  
  </div>
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  <div>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">EXHIBIT
  INDEX</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <table border="0" cellspacing="0" cellpadding="0" width="100%" style="border-collapse:collapse;width:100.0%;">
   <tr>
    <td width="10%" valign="bottom" style="border:none;border-bottom:solid windowtext 1.0pt;padding:0in .7pt 0in .7pt;width:10.76%;">
    <p style="margin:0in 0in .0001pt;"><b><font size="1" face="Times New Roman" style="font-size:8.0pt;font-weight:bold;">Exhibit&nbsp;Number</font></b></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:2.08%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="1" face="Times New Roman" style="font-size:1.0pt;font-weight:bold;">&nbsp;</font></b></p>
    </td>
    <td width="87%" valign="bottom" style="border:none;border-bottom:solid windowtext 1.0pt;padding:0in .7pt 0in .7pt;width:87.16%;">
    <p style="margin:0in 0in .0001pt;"><b><font size="1" face="Times New Roman" style="font-size:8.0pt;font-weight:bold;">Exhibit&nbsp;Title</font></b></p>
    </td>
   </tr>
   <tr>
    <td width="10%" valign="top" style="border:none;padding:0in .7pt 0in .7pt;width:10.76%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">99.1</font></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:2.08%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="87%" valign="top" style="border:none;padding:0in .7pt 0in .7pt;width:87.16%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Supplemental
    information dated March&nbsp;31, 2008 for Corporate Office Properties Trust.</font></p>
    </td>
   </tr>
  </table>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">10</font></p>
  
  <div style="margin:0in 0in .0001pt;text-indent:0in;"><hr size="3" width="100%" noshade color="#010101" align="left"></div>
  
  </div>
  <!-- SEQ.=1,FOLIO='10',FILE='C:\JMS\jtaylora\08-13414-1\task2916504\13414-1-ba.htm',USER='jtaylora',CD='May  5 22:43 2008' -->
  
  
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metadata_documents: [{"type": "8-K", "sequence": "1", "filename": "a08-13414_18k.htm", "description": "8-K", "secsgml_size_bytes": 75936}]
metadata_filer: {"company-data": {"conformed-name": "CORPORATE OFFICE PROPERTIES TRUST", "cik": "0000860546", "assigned-sic": "6798", "irs-number": "232947217", "state-of-incorporation": "MD", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "8-K", "act": "34", "file-number": "001-14023", "film-number": "08807321"}, "business-address": {"street1": "8815 CENTRE PARK DR", "street2": "SUITE 400", "city": "COLUMBIA", "state": "MD", "zip": "21045", "phone": "6105381800"}, "mail-address": {"street1": "8815 CENTRE PARK DR", "street2": "SUITE 400", "city": "COLUMBIA", "state": "MD", "zip": "21045"}, "former-company": [{"former-conformed-name": "CORPORATE OFFICE PROPERTIES TRUST INC", "date-changed": "19980105"}, {"former-conformed-name": "ROYALE INVESTMENTS INC", "date-changed": "19930328"}, {"former-conformed-name": "ROYALE REIT INC", "date-changed": "19600201"}]}
text: UNITED
  STATES
  SECURITIES AND EXCHANGE COMMISSION
  Washington, DC  20549
  FORM 8-K
  CURRENT
  REPORT
  Pursuant
  to Section 13 or 15(d) of
  the Securities Exchange Act of 1934
  Date of report (Date of earliest event reported)
  May 6,
  2008 (May 6, 2008)
  CORPORATE
  OFFICE PROPERTIES TRUST
  (Exact name of registrant as specified in its charter)
  Maryland
  1-14023
  23-2947217
  (State or other jurisdiction of
  incorporation)
  (Commission
  File Number)
  (IRS Employer
  Identification Number)
  6711 Columbia Gateway Drive, Suite 300
  Columbia, Maryland 21046
  (Address of principal executive offices)
  (443) 285-5400
  (Registrant's telephone number, including area code)
  Check
  the appropriate box below if the Form 8-K filing is intended to
  simultaneously satisfy the filing obligation of the registrant under any of the
  following provisions (see General Instruction A.2 below):
  o
  Written communications pursuant to Rule 425 under the Securities Act (17
  CFR 230.425)
  o
  Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR
  240.14a-12)
  o
  Pre-commencement communications pursuant to Rule 14d-2(b) under the
  Exchange Act (17 CFR 240.14d-2(b))
  o
  Pre-commencement communications pursuant to Rule 13e-4(c) under the
  Exchange Act (17 CFR 240.13e-4(c))
  Item 2.02.              Results
  of Operations and Financial Condition
  In connection with its release of
  earnings on May 6, 2008, the Registrant is making available certain
  additional information pertaining to its properties and operations as of and
  for the period ended March 31, 2008. 
  This information is furnished herewith as Exhibit 99.1 and is
  incorporated herein by reference.
  The information included herein,
  including the exhibits, shall not be deemed "filed" for any purpose, including
  the purposes of Section 18 of the Securities Exchange Act of 1934, as
  amended (the "Exchange Act"), or subject to liabilities of that Section.  The information included herein, including
  the exhibits, shall also not be deemed incorporated by reference into any
  filing under the Securities Act of 1933, as amended (the "Securities Act"), or
  the Exchange Act regardless of any general incorporation language in such
  filing.
  The Registrant uses non-GAAP
  financial measures in earnings press releases and information furnished to the
  Securities and Exchange Commission.  The
  Registrant believes that these measures are helpful to investors in measuring
  its performance and comparing such performance to other real estate investment
  trusts ("REITs").  Descriptions of these
  measures are set forth below.
  Funds from operations ("FFO")
  Funds
  from operations ("FFO") is defined as net income computed using GAAP, excluding
  gains (or losses) from sales of real estate, plus real estate-related
  depreciation and amortization after adjustments for unconsolidated partnerships
  and joint ventures.  Gains from the sale
  of real estate that are attributable to sales of non-operating properties are
  included in FFO.  Gains from sales of
  newly-developed properties less accumulated depreciation, if any, required
  under GAAP are also included in FFO on the basis that development services are
  the primary revenue generating activity; the Registrant believes that inclusion
  of these development gains is in accordance with the National Association of
  Real Estate Investment Trusts' ("NAREIT") definition of FFO, although others
  may interpret the definition differently.
  Accounting for real estate assets using historical cost
  accounting under GAAP assumes that the value of real estate assets diminishes
  predictably over time.  NAREIT stated in
  its April 2002 White Paper on Funds from Operations that "since real
  estate asset values have historically risen or fallen with market conditions,
  many industry investors have considered presentations of operating results for
  real estate companies that use historical cost accounting to be insufficient by
  themselves."  As a result, the concept of
  FFO was created by NAREIT for the REIT industry to "address this problem."  The Registrant agrees with the concept of FFO
  and believes that FFO is useful to management and investors as a supplemental
  measure of operating performance because, by excluding gains and losses related
  to sales of previously depreciated operating real estate properties and
  excluding real estate-related depreciation and amortization, FFO can help one
  compare the Registrant's operating performance between periods.  In addition, since most equity REITs provide
  FFO information to the investment community, the Registrant believes that FFO
  is useful to investors as a supplemental measure for comparing its results to
  those of other equity REITs. The Registrant believes that net income is the
  most directly comparable GAAP measure to FFO.
  Since FFO excludes certain items
  includable in net income, reliance on the measure has limitations; management
  compensates for these limitations by using the measure simply as a supplemental
  measure that is weighed in the balance with other GAAP and non-GAAP
  measures.
  2
  FFO is not necessarily an
  indication of the Registrant's cash flow available to fund cash needs.  Additionally, it should not be used as an
  alternative to net income when evaluating the Registrant's financial
  performance or to cash flow from operating, investing and financing activities
  when evaluating the Registrant's liquidity or ability to make cash
  distributions or pay debt service.  The
  FFO presented by the Registrant may not be comparable to the FFO presented by
  other REITs since they may interpret the current NAREIT definition of FFO
  differently or they may not use the current NAREIT definition of FFO.
  Funds from operations-Basic ("Basic FFO")
  Basic FFO is FFO adjusted to (1) subtract (a) preferred
  share dividends and (b) issuance costs associated with redeemed preferred
  shares and (2) add back GAAP net income allocated to common units in
  Corporate Office Properties, L.P. (the "Operating Partnership") not owned by
  the Registrant.  With these adjustments,
  Basic FFO represents FFO available to common shareholders and common
  unitholders.  Common units in the
  Operating Partnership are substantially similar to common shares of beneficial
  interest in the Registrant ("common shares"); common units in the Operating
  Partnership are also exchangeable into common shares, subject to certain
  conditions.  The Registrant believes that
  Basic FFO is useful to investors due to the close correlation of common units
  to common shares.  The Registrant
  believes that net income is the most directly comparable GAAP measure to Basic
  FFO. Basic FFO has essentially the same
  limitations as FFO; management compensates for these limitations in essentially
  the same manner as described above for FFO.
  FFO per diluted share ("Diluted FFO per share")
  Diluted FFO per share is (1) Basic FFO adjusted to add
  back any convertible preferred share dividends and any other changes in Basic
  FFO that would result from the assumed conversion of securities that are
  convertible or exchangeable into common shares divided by (2) the sum of
  the (a) weighted average common shares outstanding during a period, (b) weighted
  average common units outstanding during a period and (c) weighted average
  number of potential additional common shares that would have been outstanding
  during a period if other securities that are convertible or exchangeable into
  common shares were converted or exchanged. 
  However, the computation of Diluted FFO per share does not assume
  conversion of securities that are convertible into common shares if the
  conversion of those securities would increase Diluted FFO per share in a given
  period.  The Registrant believes that
  Diluted FFO per share is useful to investors because it provides investors with
  a further context for evaluating its FFO results in the same manner that
  investors use earnings per share in evaluating net income available to common
  shareholders.  In addition, since most
  equity REITs provide Diluted FFO per share information to the investment
  community, the Registrant believes Diluted FFO per share is a useful
  supplemental measure for comparing the Registrant to other equity REITs.  The Registrant believes that diluted EPS is
  the most directly comparable GAAP measure to Diluted FFO per share.  Diluted FFO per share has most of the same limitations as Diluted FFO (described
  below); management compensates for these limitations in essentially the same
  manner as described below for Diluted FFO.
  Funds from operations-diluted ("Diluted FFO")
  Diluted FFO is Basic FFO adjusted to add back any convertible
  preferred share dividends and any other changes in Basic FFO that would result from
  the assumed conversion of securities that are convertible or exchangeable into
  common shares.  However, the computation
  of Diluted FFO does not assume conversion of securities that are convertible
  into common shares if the conversion of those securities would increase Diluted
  FFO per share in a given period.  The
  Registrant believes that Diluted FFO is useful to investors because it is the
  numerator used to compute Diluted FFO per share.  In addition, since most equity REITs provide
  Diluted FFO
  3
  information to the investment community, the Registrant
  believes Diluted FFO is a useful supplemental measure for comparing the
  Registrant to other equity REITs.  The
  Registrant believes that the numerator to diluted EPS is the most directly
  comparable GAAP measure to Diluted FFO.  Since Diluted FFO excludes certain items
  includable in the numerator to diluted EPS, reliance on the measure has
  limitations; management compensates for these limitations by using the measure
  simply as a supplemental measure that is weighed in the balance with other GAAP
  and non-GAAP measures.  Diluted FFO is
  not necessarily an indication of the Registrant's cash flow available to fund
  cash needs.  Additionally, it should not
  be used as an alternative to net income when evaluating the Registrant's
  financial performance or to cash flow from operating, investing and financing
  activities when evaluating the Registrant's liquidity or ability to make cash
  distributions or pay debt service.  The
  Diluted FFO presented by the Registrant may not be comparable to the Diluted
  FFO presented by other REITs.
  Adjusted funds from operations-diluted ("Diluted AFFO")
  Diluted AFFO is Diluted FFO adjusted
  for the following: (1) the elimination of the effect of (a) noncash
  rental revenues (comprised of straight-line rental adjustments, which includes
  the amortization of recurring tenant incentives, and amortization of deferred
  market rental revenue, both of which are described under "Cash NOI" below) and (b) accounting
  charges for original issuance costs associated with redeemed preferred shares;
  and (2) recurring capital expenditures (defined below).  The Registrant believes that Diluted AFFO is
  an important supplemental measure of liquidity for an equity REIT because it
  provides management and investors with an indication of its ability to incur
  and service debt and to fund dividends and other cash needs.  In addition, since most equity REITs provide
  Diluted AFFO information to the investment community, the Registrant believes
  that Diluted AFFO is a useful supplemental measure for comparing the Registrant
  to other equity REITs.  The Registrant
  believes that the numerator to diluted EPS is the most directly comparable GAAP
  measure to Diluted AFFO.  Since Diluted AFFO excludes certain items
  includable in the numerator to diluted EPS, reliance on the measure has
  limitations; management compensates for these limitations by using the measure
  simply as a supplemental measure that is weighed in the balance with other GAAP
  and non-GAAP measures.  In addition, see
  the discussion below regarding the limitations of recurring capital
  expenditures, which is used to derive Diluted AFFO.  Diluted AFFO is not necessarily an indication
  of the Registrant's cash flow available to fund cash needs.  Additionally, it should not be used as an
  alternative to net income when evaluating the Registrant's financial
  performance or to cash flow from operating, investing and financing activities
  when evaluating the Registrant's liquidity or ability to make cash
  distributions or pay debt service.  The
  Diluted AFFO presented by the Registrant may not be comparable to similar
  measures presented by other equity REITs.
  Recurring capital expenditures
  Recurring capital expenditures are defined as capital
  expenditures, tenant improvements and incentives and leasing costs associated
  with operating properties that are not (1) items contemplated prior to the
  acquisition of a property, (2) improvements associated with the expansion
  of a building or its improvements, (3) renovations to a building which
  change the underlying classification of the building (for example, from
  industrial to office or Class C office to Class B office) or (4) capital
  improvements that represent the addition of something new to the property
  rather than the replacement of something (for example, the addition of a new
  heating and air conditioning unit that is not replacing one that was previously
  there).  The Registrant believes that
  recurring capital expenditures is an important measure of performance for a
  REIT because it provides a measure of the capital expenditures that the
  Registrant can expect to incur on an ongoing basis, which is significant to how
  the Registrant manages its business since these expenditures are funded using cash
  flow from operations.  As a result, the
  measure provides a further indication of the cash flow from operations that is
  available to fund other uses.  The
  4
  Registrant believes that tenant improvements and incentives,
  capital improvements and leasing costs associated with operating properties are
  the most directly comparable GAAP measures. 
  Recurring capital expenditures do not reflect all capital expenditures
  incurred by the Registrant for the periods reported; the Registrant compensates
  for this limitation by also using the comparable GAAP measure.  The recurring
  capital expenditures presented by the
  Registrant may not be comparable to the recurring capital expenditures
  presented by other REITs.
  Combined real estate revenue
  Combined real estate revenue is total revenue from real
  estate operations, including rental revenue and tenant recoveries and other
  revenue, including discontinued operations. 
  The Registrant uses this measure to evaluate the revenue produced by its
  real estate properties, including those reported in discontinued operations.
  The Registrant believes that total revenue is the most directly comparable GAAP
  measure to combined real estate revenue. 
  Combined real estate revenue excludes other types of revenue earned by
  the Registrant, including construction contract and other service operations
  revenues. The measure also includes discontinued operations and, by doing so,
  does not reflect the overall operating performance of the Registrant's
  continuing operations.  Management compensates for these limitations by
  evaluating this measure in conjunction with the most directly comparable
  GAAP measure and other operating statistics involving revenue.
  Combined net operating income ("Combined NOI")
  Combined NOI is combined real estate revenue reduced by total
  property expenses associated with real estate operations, including
  discontinued operations; total property expenses, as used in this definition,
  do not include depreciation, amortization or interest expense associated with
  real estate operations.  The Registrant
  believes that Combined NOI is an important supplemental measure of operating
  performance for a REIT's operating real estate because it provides a measure of
  the core real estate operations, rather than factoring in depreciation and
  amortization or corporate financing and general and administrative expenses;
  this measure is particularly useful in the opinion of the Registrant in
  evaluating the performance of geographic segments, same-office property
  groupings and individual properties.  The
  Registrant believes that net income is the most directly comparable GAAP
  measure to Combined NOI.  The measure
  excludes many items that are includable in net income; management compensates for this limitation by using the measure simply as
  a supplemental measure that is weighed in the balance with other GAAP and
  non-GAAP measures.  It should not be used as an alternative to net
  income when evaluating the Registrant's financial performance or to cash flow
  from operating, investing and financing activities when evaluating the
  Registrant's liquidity or ability to make cash distributions or pay debt
  service.  Combined NOI presented
  by the Registrant may not be comparable to Combined NOI presented by other equity
  REITs that define the measure differently.
  Cash net operating income ("Cash NOI")
  Cash NOI is Combined NOI (defined above) adjusted to
  eliminate the effects of noncash rental revenues (comprised of straight-line
  rental adjustments, which includes the amortization of recurring tenant
  incentives, and amortization of deferred market rental revenue).  Under GAAP, rental revenue is recognized
  evenly over the term of tenant leases. 
  Many leases provide for contractual rent increases and the effect of
  accounting under GAAP for such leases is to accelerate the recognition of lease
  revenue.  Since some leases provide for
  periods under the lease in which rental concessions are provided to tenants,
  the effect of accounting under GAAP is to allocate rental revenue to such
  periods.  Also under GAAP, when a
  property is acquired, in-place operating leases carrying rents above or below
  market are valued as of the date of the acquisition; such value is then
  amortized into rental revenue over the lives of the related leases.
  5
  The Registrant believes that Cash NOI is an important
  supplemental measure of operating performance for a REIT's operating real
  estate because it makes adjustments to Combined NOI for revenue that is not
  associated with cash to the Registrant. 
  As is the case with Combined NOI, the measure is useful in the opinion
  of the Registrant in evaluating and comparing the performance of geographic
  segments, same-office property groupings and individual properties, although,
  since it adjusts for noncash items, it provides management and investors with a
  further indication of the Registrant's ability to incur and service debt and to
  fund dividends and other cash needs.  The
  Registrant believes that net income is the most directly comparable GAAP
  measure to Cash NOI.  The measure
  excludes many items that are includable in net income; management compensates for this limitation by using the measure simply as
  a supplemental measure that is weighed in the balance with other GAAP and
  non-GAAP measures.  It should not be used as an alternative to net
  income when evaluating the Registrant's financial performance or to cash flow
  from operating, investing and financing activities when evaluating the
  Registrant's liquidity or ability to make cash distributions or pay debt
  service.  The Cash NOI that the
  Registrant presents may not be comparable to similar measures presented by
  other equity REITs.
  Cash NOI adjusted for lease termination fees
  This measure is Cash NOI (defined above) adjusted to
  eliminate the effects of lease termination fees paid by tenants to terminate
  their lease obligations prior to the end of the agreed lease terms.  Lease termination fees are often recognized
  as revenue in large one-time lump sum amounts upon the termination of tenant
  leases.  The Registrant believes that
  Cash NOI adjusted for lease termination fees is a useful supplemental measure
  of operating performance in evaluating same-office property groupings because
  it provides a means of evaluating the effect that lease terminations had on the
  performance of the property groupings. 
  As in the case of Cash NOI, since the measure adjusts for noncash items,
  it also provides management and investors with a further indication of the
  Registrant's ability to incur and service debt and to fund dividends and other
  cash needs.  The Registrant believes that
  net income is the most directly comparable GAAP measure to Cash NOI adjusted
  for termination fees.  The measure has essentially the same limitations as Cash
  NOI as well as the further limitation of not reflecting the effect of
  lease termination fees in accordance with GAAP.  Management compensates for these
  limitations by using the measure simply as a supplemental measure that is
  weighed in the balance with other GAAP and non-GAAP measures.
  Earnings Before Interest, Income Taxes, Depreciation and
  Amortization ("EBITDA")
  EBITDA
  is net income adjusted for the effects of interest expense, depreciation and
  amortization, income taxes and minority interests.  The Registrant believes that EBITDA is an
  important measure of performance for a REIT because it provides a further tool
  to evaluate the Registrant's ability to incur and service debt and to fund dividends
  and other cash needs that supplements the previously described non-GAAP
  measures and to compare the Registrant's operating performance with that of
  other companies.  The Registrant believes
  that net income is the most directly comparable GAAP measure to EBITDA.  EBITDA excludes items that are included in
  net income, including some that require cash outlays; management compensates
  for this limitation by using the measure simply as a supplemental measure that
  is weighed in the balance with other GAAP and non-GAAP measures.   It should not be used as an alternative to
  net income when evaluating the Registrant's financial performance or to cash
  flow from operating, investing and financing activities when evaluating the
  Registrant's liquidity or ability to make cash distributions or pay debt
  service.  Additionally, EBITDA as
  reported by the Registrant may not be comparable to EBITDA reported by other
  equity REITs.
  6
  Interest
  Coverage Ratio-Combined NOI and Interest Coverage Ratio-EBITDA
  These
  measures divide either combined NOI or EBITDA by interest expense on continuing
  and discontinued operations.  The
  Registrant believes that these ratios are useful measures in evaluating the
  relationship of earnings to the total cash flow requirements for interest on
  loans associated with operating properties and, as such, are important tools in
  the Registrant's finance policy management.
  Debt
  Service Coverage Ratio-Combined NOI and Debt Service Coverage Ratio-EBITDA
  These
  measures divide either combined NOI or EBITDA by the sum of interest expense on
  continuing and discontinued operations and scheduled principal amortization on
  mortgage loans for continuing and discontinued operations.  The Registrant believes that these ratios are
  useful measures in evaluating the relationship of earnings to the total cash
  flow requirements of loans associated with operating properties and, as such,
  are important tools in the Registrant's finance policy management.
  Fixed
  Charge Coverage Ratio-Combined NOI and Fixed Charge Coverage Ratio-EBITDA
  These
  measures divide either combined NOI or EBITDA by the sum of (1) interest
  expense on continuing and discontinued operations, (2) dividends on
  preferred shares and (3) distributions on preferred units in the Operating
  Partnership not owned by the Registrant. 
  The Registrant believes that these ratios are useful measures in
  evaluating the relationship of earnings to the cash flow requirements of (1) interest
  expense on loans associated with operating properties and (2) dividends to
  preferred equity holders and, as such, are important tools in the Registrant's
  finance policy management.
  Combined
  NOI as a Percentage of Combined Real Estate Revenues and EBITDA as a Percentage
  of Combined Real Estate Revenues
  These
  measures divide either Combined NOI or EBITDA by total real estate revenues
  from continuing and discontinued operations. 
  The Registrant believes that net income divided by combined real estate
  revenue is the most directly comparable GAAP measure to these two measures.
  General
  and Administrative Expenses as a Percentage of Combined Real Estate Revenue or
  EBITDA
  These
  measures divide general and administrative expenses by either Combined Real
  Estate Revenue or EBITDA.  The Registrant
  believes that general and administrative expenses divided by net income is the
  most directly comparable GAAP measure.
  Recurring
  Capital Expenditures as a Percentage of Combined NOI
  This
  measure divides recurring capital expenditures by NOI.
  FFO
  Diluted Payout Ratio and AFFO Diluted Payout Ratio
  These
  measures are defined as (1) the sum of (A) dividends on common shares
  and (B) dividends on common and convertible preferred shares and
  distributions to holders of interests in the Operating Partnership when such
  dividends and distributions are included in Diluted FFO and Diluted AFFO
  divided by (2) either Diluted FFO or Diluted AFFO.  The Registrant believes that these ratios are
  useful to investors as supplemental measures of its ability to make
  distributions to investors.  In addition,
  since most equity REITs provide these ratios, the Registrant believes they are
  useful supplemental measures for comparing the Registrant to other equity
  REITs.  The Registrant believes that Earnings
  Payout Ratio is the most comparable GAAP measure.  Earnings Payout Ratio is defined as dividends
  on common shares divided by net income available to common shareholders.  Since FFO Diluted Payout Ratio and AFFO
  Diluted Payout Ratio are derived from Diluted FFO and Diluted AFFO, they share
  the limitations previously discussed for
  7
  those
  measures; management compensates for these limitations by using the measures
  simply as supplemental measures that are weighed in the balance with other GAAP
  and non-GAAP measures.
  Dividend
  Coverage-FFO Diluted and Dividend Coverage-AFFO Diluted
  These
  measures divide either Diluted FFO or Diluted AFFO by the sum of (1) dividends
  on common shares and (2) dividends on common and convertible preferred
  shares and distributions to holders of interests in the Operating Partnership
  when such dividends and distributions are included in Diluted FFO and Diluted
  AFFO.
  Debt
  to Undepreciated Book Value of Real Estate Assets
  This
  measure is defined as mortgage loans payable divided by net investment in real
  estate presented on the Registrant's consolidated balance sheet excluding the
  effect of accumulated depreciation incurred to date on such real estate.  The Registrant believes that the measure of
  Debt to Undepreciated Real Estate Assets is useful to management and investors
  as a supplemental measure of its borrowing levels.  In addition, since most equity REITs provide
  Debt to Undepreciated Real Estate Asset information, the Registrant believes
  Debt to Undepreciated Real Estate Assets is a useful supplemental measure for
  comparing the Registrant to other equity REITs. 
  The Registrant believes that the measure of Debt to Total Assets,
  defined as mortgage loans payable divided by total assets, is the most comparable
  GAAP measure.  Debt to Undepreciated Real
  Estate Assets excludes the effect of accumulated depreciation, other assets and
  other liabilities; management compensates for these limitations by using the
  measure simply as a supplemental measure that is weighed with the comparable
  GAAP measure and other GAAP and non-GAAP measures.
  Item 9.01.              Financial
  Statements and Exhibits
  (a)
  Financial
    Statements of Businesses Acquired
  None
  (b)
  Pro
    Forma Financial Information
  None
  (c)
  Shell
    Company Transactions
  None
  (d)
  Exhibits
  Exhibit Number
  Description
  99.1
  Supplemental
    information dated March 31, 2008 for Corporate Office Properties Trust.
  8
  SIGNATURES
  Pursuant to the
  requirements of the Securities Exchange Act of 1934, the Registrant has duly
  caused this Report to be signed on its behalf by the undersigned hereunto duly
  authorized.
  Dated: May 6, 2008
  CORPORATE OFFICE PROPERTIES TRUST
  By:
  /s/ Randall M. Griffin
  Name:
  Randall M. Griffin
  Title:
  President and Chief Executive Officer
  By:
  /s/ Stephen E. Riffee
  Name:
  Stephen E. Riffee
  Title:
  Executive Vice President
    and
  Chief Financial Officer
  9
  EXHIBIT
  INDEX
  Exhibit Number
  Exhibit Title
  99.1
  Supplemental
    information dated March 31, 2008 for Corporate Office Properties Trust.
  10