<html>
<head>


  </head>
<body lang="EN-US">
<div>
<div style="border-bottom:solid windowtext 1.0pt;border-left:none;border-right:none;border-top:solid windowtext 3.0pt;padding:1.0pt 0in 1.0pt 0in;">
<p style="border:none;margin:0in 0in .0001pt;padding:0in;"><font size="1" face="Times New Roman" style="font-size:1.0pt;">&#150;</font></p>
</div>
<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;">&nbsp;</font></b></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;">UNITED STATES</font></b></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;">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&nbsp; 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</font></b></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;">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>September&nbsp;9, 2013</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></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, L.P.</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;">(Exact name of registrant as specified in its charter)</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>
<div align="center">
<table border="0" cellspacing="0" cellpadding="0" width="100%" style="border-collapse:collapse;width:100.0%;">
<tr>
<td width="30%" valign="top" style="padding:0in 0in 0in 0in;width:30.96%;">
<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;">Corporate Office Properties Trust</font></b></p>    </td>
<td width="1%" valign="bottom" style="padding:0in 0in 0in 0in;width:1.0%;">
<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="25%" valign="top" style="padding:0in 0in 0in 0in;width:25.0%;">
<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="1%" valign="bottom" style="padding:0in 0in 0in 0in;width:1.0%;">
<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="20%" valign="top" style="padding:0in 0in 0in 0in;width:20.0%;">
<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 0in 0in 0in;width:2.04%;">
<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="20%" valign="top" style="padding:0in 0in 0in 0in;width:20.0%;">
<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="30%" valign="top" style="padding:0in 0in 0in 0in;width:30.96%;">
<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="1%" valign="bottom" style="padding:0in 0in 0in 0in;width:1.0%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="25%" valign="top" style="padding:0in 0in 0in 0in;width:25.0%;">
<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</font></p>    </td>
<td width="1%" valign="bottom" style="padding:0in 0in 0in 0in;width:1.0%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="20%" valign="top" style="padding:0in 0in 0in 0in;width:20.0%;">
<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(Commission File</font></p>    </td>
<td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.04%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="20%" valign="top" style="padding:0in 0in 0in 0in;width:20.0%;">
<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</font></p>    </td>   </tr>
<tr>
<td width="30%" valign="top" style="padding:0in 0in 0in 0in;width:30.96%;">
<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="1%" valign="bottom" style="padding:0in 0in 0in 0in;width:1.0%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="25%" valign="top" style="padding:0in 0in 0in 0in;width:25.0%;">
<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">incorporation or organization)</font></p>    </td>
<td width="1%" valign="bottom" style="padding:0in 0in 0in 0in;width:1.0%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="20%" valign="top" style="padding:0in 0in 0in 0in;width:20.0%;">
<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Number)</font></p>    </td>
<td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.04%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="20%" valign="top" style="padding:0in 0in 0in 0in;width:20.0%;">
<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Identification No.)</font></p>    </td>   </tr>
<tr>
<td width="30%" valign="top" style="padding:0in 0in 0in 0in;width:30.96%;">
<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;">&nbsp;</font></b></p>    </td>
<td width="1%" valign="bottom" style="padding:0in 0in 0in 0in;width:1.0%;">
<p style="margin:0in 0in .0001pt;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">&nbsp;</font></b></p>    </td>
<td width="25%" valign="top" style="padding:0in 0in 0in 0in;width:25.0%;">
<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;">&nbsp;</font></b></p>    </td>
<td width="1%" valign="bottom" style="padding:0in 0in 0in 0in;width:1.0%;">
<p style="margin:0in 0in .0001pt;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">&nbsp;</font></b></p>    </td>
<td width="20%" valign="top" style="padding:0in 0in 0in 0in;width:20.0%;">
<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;">&nbsp;</font></b></p>    </td>
<td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.04%;">
<p style="margin:0in 0in .0001pt;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">&nbsp;</font></b></p>    </td>
<td width="20%" valign="top" style="padding:0in 0in 0in 0in;width:20.0%;">
<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;">&nbsp;</font></b></p>    </td>   </tr>
<tr>
<td width="30%" valign="top" style="padding:0in 0in 0in 0in;width:30.96%;">
<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;">Corporate Office Properties, L.P.</font></b></p>    </td>
<td width="1%" valign="bottom" style="padding:0in 0in 0in 0in;width:1.0%;">
<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="25%" valign="top" style="padding:0in 0in 0in 0in;width:25.0%;">
<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;">Delaware</font></b></p>    </td>
<td width="1%" valign="bottom" style="padding:0in 0in 0in 0in;width:1.0%;">
<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="20%" valign="top" style="padding:0in 0in 0in 0in;width:20.0%;">
<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;">333-189188</font></b></p>    </td>
<td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.04%;">
<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="20%" valign="top" style="padding:0in 0in 0in 0in;width:20.0%;">
<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;">23-2930022</font></b></p>    </td>   </tr>
<tr>
<td width="30%" valign="top" style="padding:0in 0in 0in 0in;width:30.96%;">
<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="1%" valign="bottom" style="padding:0in 0in 0in 0in;width:1.0%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="25%" valign="top" style="padding:0in 0in 0in 0in;width:25.0%;">
<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</font></p>    </td>
<td width="1%" valign="bottom" style="padding:0in 0in 0in 0in;width:1.0%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="20%" valign="top" style="padding:0in 0in 0in 0in;width:20.0%;">
<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(Commission File</font></p>    </td>
<td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.04%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="20%" valign="top" style="padding:0in 0in 0in 0in;width:20.0%;">
<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</font></p>    </td>   </tr>
<tr>
<td width="30%" valign="top" style="padding:0in 0in 0in 0in;width:30.96%;">
<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="1%" valign="bottom" style="padding:0in 0in 0in 0in;width:1.0%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="25%" valign="top" style="padding:0in 0in 0in 0in;width:25.0%;">
<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">incorporation or organization)</font></p>    </td>
<td width="1%" valign="bottom" style="padding:0in 0in 0in 0in;width:1.0%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="20%" valign="top" style="padding:0in 0in 0in 0in;width:20.0%;">
<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Number)</font></p>    </td>
<td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.04%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="20%" valign="top" style="padding:0in 0in 0in 0in;width:20.0%;">
<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Identification No.)</font></p>    </td>   </tr>  </table>
</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="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">6711 Columbia Gateway Drive, Suite&nbsp;300</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;">Columbia, Maryland 21046</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;">(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></p>
<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(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>
<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 0in 0in 0in;width:5.66%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Wingdings" style="font-size:10.0pt;">o</font></p>    </td>
<td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.38%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="91%" valign="top" style="padding:0in 0in 0in 0in;width:91.96%;">
<p style="margin:0in 0in .0001pt;"><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>    </td>   </tr>
<tr>
<td width="5%" valign="top" style="padding:0in 0in 0in 0in;width:5.66%;">
<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 0in 0in 0in;width:2.38%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="91%" valign="top" style="padding:0in 0in 0in 0in;width:91.96%;">
<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="5%" valign="top" style="padding:0in 0in 0in 0in;width:5.66%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Wingdings" style="font-size:10.0pt;">o</font></p>    </td>
<td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.38%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="91%" valign="top" style="padding:0in 0in 0in 0in;width:91.96%;">
<p style="margin:0in 0in .0001pt;"><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>    </td>   </tr>
<tr>
<td width="5%" valign="top" style="padding:0in 0in 0in 0in;width:5.66%;">
<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 0in 0in 0in;width:2.38%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="91%" valign="top" style="padding:0in 0in 0in 0in;width:91.96%;">
<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="5%" valign="top" style="padding:0in 0in 0in 0in;width:5.66%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Wingdings" style="font-size:10.0pt;">o</font></p>    </td>
<td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.38%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="91%" valign="top" style="padding:0in 0in 0in 0in;width:91.96%;">
<p style="margin:0in 0in .0001pt;"><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>    </td>   </tr>
<tr>
<td width="5%" valign="top" style="padding:0in 0in 0in 0in;width:5.66%;">
<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 0in 0in 0in;width:2.38%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="91%" valign="top" style="padding:0in 0in 0in 0in;width:91.96%;">
<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="5%" valign="top" style="padding:0in 0in 0in 0in;width:5.66%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Wingdings" style="font-size:10.0pt;">o</font></p>    </td>
<td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.38%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="91%" valign="top" style="padding:0in 0in 0in 0in;width:91.96%;">
<p style="margin:0in 0in .0001pt;"><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>    </td>   </tr>  </table>
<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 style="border-bottom:solid windowtext 3.0pt;border-left:none;border-right:none;border-top:solid windowtext 1.0pt;padding:1.0pt 0in 1.0pt 0in;">
<p style="border:none;margin:0in 0in .0001pt;padding:0in;"><font size="1" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
</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>
<div style="margin:0in 0in .0001pt;"><hr size="3" width="100%" noshade color="#010101" align="left"></div>
</div>
<!-- SEQ.=1,FOLIO='',FILE='C:\JMS\105933\13-20374-2\task6249785\20374-2-ba.htm',USER='105933',CD='Sep 14 02:32 2013' -->

<br clear="all" style="page-break-before:always;">
<div style="font-family:Times New Roman;">
<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;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">Item 8.01&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; Other Events</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:24.5pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">On September&nbsp;9, 2013, Corporate Office Properties, L.P. (the &#147;Operating Partnership&#148;), the operating partnership of Corporate Office Properties Trust (the &#147;Company&#148;), priced a public offering (the &#147;Offering&#148;) of $250 million aggregate principal amount of its 5.25% Senior Notes due 2024 (the &#147;Notes&#148;).&#160; In connection with the Offering, the Company and the Operating Partnership entered into an Underwriting Agreement with Wells Fargo Securities, LLC, Barclays Capital Inc. and Citigroup Global Markets Inc., as representatives of the several underwriters named therein, that provides for the issuance and sale of the Notes by the Operating Partnership.&#160; The offering of the Notes is registered under the Securities Act of 1933, as amended, pursuant to the Registration Statement on Form&nbsp;S-3 (File No.&nbsp;333-190137) filed by the Company and the Operating Partnership with the Securities and Exchange Commission (the &#147;Commission) on July&nbsp;25, 2013 (the &#147;Registration Statement&#148;).&#160; The terms of the Notes, which will be issued on September&nbsp;16, 2013, will be governed by a senior indenture, to be dated September&nbsp;16, 2013, by and among the Operating Partnership, as issuer, the Company, as guarantor, and U.S. Bank National Association, as trustee (the &#147;Base Indenture&#148;), as supplemented and amended by a supplemental indenture thereto, to be dated September&nbsp;16, 2013 (the &#147;First Supplemental Indenture,&#148; and together with the Base Indenture, the &#147;Indenture&#148;).</font></p>
<p style="margin:0in 0in .0001pt;text-indent:24.5pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
<p style="margin:0in 0in .0001pt;text-indent:24.5pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">A copy of the form of Base Indenture was previously filed as Exhibit&nbsp;4.1 to the Registration Statement and is incorporated by reference herein.&#160; Copies of the Underwriting Agreement, the form of Global Note and the form of First Supplemental Indenture are filed as Exhibits 1.1, 4.1 and 4.2 hereto, respectively, and are incorporated by reference herein.&#160; The summaries of the Underwriting Agreement, the Notes and the Indenture in this Current Report on Form&nbsp;8-K do not purport to be complete and are qualified in their entirety by reference to Exhibits 1.1, 4.1 and 4.2 to this Current Report on Form&nbsp;8-K.</font></p>
<p style="margin:0in 0in .0001pt;text-indent:24.5pt;"><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</font></b><b><font size="1" style="font-size:3.0pt;font-weight:bold;">&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; </font></b><b><font size="2" style="font-size:10.0pt;font-weight:bold;">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>
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(a)&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; Financial Statements of Businesses Acquired</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;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">None</font></p>
<p style="margin:0in 0in .0001pt;text-indent:.5in;"><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;">(b)</font><font size="1" style="font-size:3.0pt;">&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; </font><font size="2" style="font-size:10.0pt;">Pro Forma Financial Information</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;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">None</font></p>
<p style="margin:0in 0in .0001pt;text-indent:.5in;"><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;">(c)&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; Shell Company Transactions</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;text-indent:35.0pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">None</font></p>
<p style="margin:0in 0in .0001pt;text-indent:35.0pt;"><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;">(d)</font><font size="1" style="font-size:3.0pt;">&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; </font><font size="2" style="font-size:10.0pt;">Exhibits</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="14%" valign="bottom" style="border:none;border-bottom:solid windowtext 1.0pt;padding:0in 0in 0in 0in;width:14.32%;">
<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 0in 0in 0in;width:2.14%;">
<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="83%" valign="bottom" style="border:none;border-bottom:solid windowtext 1.0pt;padding:0in 0in 0in 0in;width:83.54%;">
<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><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="14%" valign="top" style="border:none;padding:0in 0in 0in 0in;width:14.32%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">1.1</font></p>    </td>
<td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.14%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="83%" valign="top" style="border:none;padding:0in 0in 0in 0in;width:83.54%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Underwriting   Agreement, dated September&nbsp;9, 2013, by and among Corporate Office   Properties Trust, Corporate Office Properties, L.P. and Wells Fargo   Securities, LLC, Barclays Capital Inc. and Citigroup Global Markets Inc., as   representatives of the several underwriters named therein</font></p>    </td>   </tr>
<tr>
<td width="14%" valign="top" style="padding:0in 0in 0in 0in;width:14.32%;">
<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 0in 0in 0in;width:2.14%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="83%" valign="top" style="padding:0in 0in 0in 0in;width:83.54%;">
<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="14%" valign="top" style="padding:0in 0in 0in 0in;width:14.32%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">4.1</font></p>    </td>
<td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.14%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="83%" valign="top" style="padding:0in 0in 0in 0in;width:83.54%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Form&nbsp;of   Global Note Representing $250,000,000 Aggregate Principal Amount of 5.25%   Senior Notes due 2024</font></p>    </td>   </tr>
<tr>
<td width="14%" valign="top" style="padding:0in 0in 0in 0in;width:14.32%;">
<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 0in 0in 0in;width:2.14%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="83%" valign="top" style="padding:0in 0in 0in 0in;width:83.54%;">
<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="14%" valign="top" style="padding:0in 0in 0in 0in;width:14.32%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">4.2</font></p>    </td>
<td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.14%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="83%" valign="top" style="padding:0in 0in 0in 0in;width:83.54%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Form&nbsp;of   First Supplemental Indenture, by and among Corporate Office Properties, L.P.,   as issuer, Corporate Office Properties Trust, as guarantor, and U.S. Bank   National Association, as trustee</font></p>    </td>   </tr>
<tr>
<td width="14%" valign="top" style="padding:0in 0in 0in 0in;width:14.32%;">
<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 0in 0in 0in;width:2.14%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="83%" valign="top" style="padding:0in 0in 0in 0in;width:83.54%;">
<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="14%" valign="top" style="padding:0in 0in 0in 0in;width:14.32%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">5.1</font></p>    </td>
<td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.14%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="83%" valign="top" style="padding:0in 0in 0in 0in;width:83.54%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Opinion   of Saul Ewing LLP regarding the validity of the Notes</font></p>    </td>   </tr>
<tr>
<td width="14%" valign="top" style="padding:0in 0in 0in 0in;width:14.32%;">
<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 0in 0in 0in;width:2.14%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="83%" valign="top" style="padding:0in 0in 0in 0in;width:83.54%;">
<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="14%" valign="top" style="padding:0in 0in 0in 0in;width:14.32%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">5.2</font></p>    </td>
<td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.14%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="83%" valign="top" style="padding:0in 0in 0in 0in;width:83.54%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Opinion   of Morgan, Lewis&nbsp;&amp; Bockius LLP regarding the validity of the Notes</font></p>    </td>   </tr>
<tr>
<td width="14%" valign="top" style="padding:0in 0in 0in 0in;width:14.32%;">
<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 0in 0in 0in;width:2.14%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="83%" valign="top" style="padding:0in 0in 0in 0in;width:83.54%;">
<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="14%" valign="top" style="padding:0in 0in 0in 0in;width:14.32%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">8.1</font></p>    </td>
<td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.14%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="83%" valign="top" style="padding:0in 0in 0in 0in;width:83.54%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Opinion   of Morgan, Lewis &amp; Bockius LLP</font></p>    </td>   </tr>
<tr>
<td width="14%" valign="top" style="padding:0in 0in 0in 0in;width:14.32%;">
<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 0in 0in 0in;width:2.14%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="83%" valign="top" style="padding:0in 0in 0in 0in;width:83.54%;">
<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="14%" valign="top" style="padding:0in 0in 0in 0in;width:14.32%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">23.1</font></p>    </td>
<td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.14%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="83%" valign="top" style="padding:0in 0in 0in 0in;width:83.54%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Consent   of Saul Ewing LLP (contained in Exhibit 5.1)</font></p>    </td>   </tr>
<tr>
<td width="14%" valign="top" style="padding:0in 0in 0in 0in;width:14.32%;">
<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 0in 0in 0in;width:2.14%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="83%" valign="top" style="padding:0in 0in 0in 0in;width:83.54%;">
<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="14%" valign="top" style="padding:0in 0in 0in 0in;width:14.32%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">23.2</font></p>    </td>
<td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.14%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="83%" valign="top" style="padding:0in 0in 0in 0in;width:83.54%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Consent   of Morgan, Lewis &amp; Bockius LLP (contained in Exhibit 5.2)</font></p>    </td>   </tr>
<tr>
<td width="14%" valign="top" style="padding:0in 0in 0in 0in;width:14.32%;">
<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 0in 0in 0in;width:2.14%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="83%" valign="top" style="padding:0in 0in 0in 0in;width:83.54%;">
<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="14%" valign="top" style="padding:0in 0in 0in 0in;width:14.32%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">23.3</font></p>    </td>
<td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.14%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="83%" valign="top" style="padding:0in 0in 0in 0in;width:83.54%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Consent   of Morgan, Lewis &amp; Bockius LLP (contained in Exhibit 8.1)</font></p>    </td>   </tr>  </table>
<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;">2<a name="PB_2_110318_5796"></a></font></p>
<div style="margin:0in 0in .0001pt;"><hr size="3" width="100%" noshade color="#010101" align="left"></div>
</div>
<!-- SEQ.=1,FOLIO='2',FILE='C:\JMS\105933\13-20374-2\task6249785\20374-2-ba.htm',USER='105933',CD='Sep 14 02:32 2013' -->

<br clear="all" style="page-break-before:always;">
<div>
<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;">&nbsp;</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;">SIGNATURES</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 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;"><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="6%" valign="top" style="padding:0in 0in 0in 0in;width:6.66%;">
<p style="margin:0in 0in .0001pt 10.0pt;text-indent:-10.0pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="44%" valign="top" style="padding:0in 0in 0in 0in;width:44.0%;">
<p style="margin:0in 0in .0001pt 10.0pt;text-indent:-10.0pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">CORPORATE OFFICE PROPERTIES TRUST</font></p>    </td>
<td width="6%" valign="top" style="padding:0in 0in 0in 0in;width:6.26%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="43%" valign="top" style="padding:0in 0in 0in 0in;width:43.08%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">CORPORATE   OFFICE PROPERTIES, L.P.</font></p>    </td>   </tr>
<tr>
<td width="6%" valign="top" style="padding:0in 0in 0in 0in;width:6.66%;">
<p style="margin:0in 0in .0001pt 10.0pt;text-indent:-10.0pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="44%" valign="top" style="padding:0in 0in 0in 0in;width:44.0%;">
<p style="margin:0in 0in .0001pt 10.0pt;text-indent:-10.0pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="6%" valign="top" style="padding:0in 0in 0in 0in;width:6.26%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="43%" valign="top" style="padding:0in 0in 0in 0in;width:43.08%;">
<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="6%" valign="top" style="padding:0in 0in 0in 0in;width:6.66%;">
<p style="margin:0in 0in .0001pt 10.0pt;text-indent:-10.0pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="44%" valign="top" style="padding:0in 0in 0in 0in;width:44.0%;">
<p style="margin:0in 0in .0001pt 10.0pt;text-indent:-10.0pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="6%" valign="top" style="padding:0in 0in 0in 0in;width:6.26%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="43%" valign="top" style="padding:0in 0in 0in 0in;width:43.08%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">By:   Corporate Office Properties Trust,</font></p>    </td>   </tr>
<tr>
<td width="6%" valign="top" style="padding:0in 0in 0in 0in;width:6.66%;">
<p style="margin:0in 0in .0001pt 10.0pt;text-indent:-10.0pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="44%" valign="top" style="padding:0in 0in 0in 0in;width:44.0%;">
<p style="margin:0in 0in .0001pt 10.0pt;text-indent:-10.0pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="6%" valign="top" style="padding:0in 0in 0in 0in;width:6.26%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="43%" valign="top" style="padding:0in 0in 0in 0in;width:43.08%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">its   General Partner</font></p>    </td>   </tr>
<tr>
<td width="6%" valign="top" style="padding:0in 0in 0in 0in;width:6.66%;">
<p style="margin:0in 0in .0001pt 10.0pt;text-indent:-10.0pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="44%" valign="top" style="padding:0in 0in 0in 0in;width:44.0%;">
<p style="margin:0in 0in .0001pt 10.0pt;text-indent:-10.0pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="6%" valign="top" style="padding:0in 0in 0in 0in;width:6.26%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="43%" valign="top" style="padding:0in 0in 0in 0in;width:43.08%;">
<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="6%" valign="top" style="padding:0in 0in 0in 0in;width:6.66%;">
<p style="margin:0in 0in .0001pt 10.0pt;text-indent:-10.0pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="44%" valign="top" style="border:none;border-bottom:solid windowtext 1.0pt;padding:0in 0in 0in 0in;width:44.0%;">
<p style="margin:0in 0in .0001pt 10.0pt;text-indent:-10.0pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">/s/ Stephen E. Riffee</font></p>    </td>
<td width="6%" valign="top" style="padding:0in 0in 0in 0in;width:6.26%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="43%" valign="top" style="border:none;border-bottom:solid windowtext 1.0pt;padding:0in 0in 0in 0in;width:43.08%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">/s/   Stephen E. Riffee</font></p>    </td>   </tr>
<tr>
<td width="6%" valign="top" style="padding:0in 0in 0in 0in;width:6.66%;">
<p style="margin:0in 0in .0001pt 10.0pt;text-indent:-10.0pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="44%" valign="top" style="border:none;padding:0in 0in 0in 0in;width:44.0%;">
<p style="margin:0in 0in .0001pt 10.0pt;text-indent:-10.0pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Stephen E. Riffee</font></p>    </td>
<td width="6%" valign="top" style="padding:0in 0in 0in 0in;width:6.26%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="43%" valign="top" style="border:none;padding:0in 0in 0in 0in;width:43.08%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Stephen   E. Riffee</font></p>    </td>   </tr>
<tr>
<td width="6%" valign="top" style="padding:0in 0in 0in 0in;width:6.66%;">
<p style="margin:0in 0in .0001pt 10.0pt;text-indent:-10.0pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="44%" valign="top" style="padding:0in 0in 0in 0in;width:44.0%;">
<p style="margin:0in 0in .0001pt 10.0pt;text-indent:-10.0pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Executive Vice President and Chief Financial   Officer</font></p>    </td>
<td width="6%" valign="top" style="padding:0in 0in 0in 0in;width:6.26%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="43%" valign="top" style="padding:0in 0in 0in 0in;width:43.08%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Executive   Vice President and Chief Financial Officer</font></p>    </td>   </tr>
<tr>
<td width="6%" valign="top" style="padding:0in 0in 0in 0in;width:6.66%;">
<p style="margin:0in 0in .0001pt 10.0pt;text-indent:-10.0pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="44%" valign="top" style="padding:0in 0in 0in 0in;width:44.0%;">
<p style="margin:0in 0in .0001pt 10.0pt;text-indent:-10.0pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="6%" valign="top" style="padding:0in 0in 0in 0in;width:6.26%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="43%" valign="top" style="padding:0in 0in 0in 0in;width:43.08%;">
<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="6%" valign="top" style="padding:0in 0in 0in 0in;width:6.66%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Dated:</font></p>    </td>
<td width="44%" valign="top" style="padding:0in 0in 0in 0in;width:44.0%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">September&nbsp;13,   2013</font></p>    </td>
<td width="6%" valign="top" style="padding:0in 0in 0in 0in;width:6.26%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Dated:</font></p>    </td>
<td width="43%" valign="top" style="padding:0in 0in 0in 0in;width:43.08%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">September&nbsp;13,   2013</font></p>    </td>   </tr>  </table>
<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;">3<a name="PB_3_110637_2897"></a></font></p>
<div style="margin:0in 0in .0001pt;"><hr size="3" width="100%" noshade color="#010101" align="left"></div>
</div>
<!-- SEQ.=1,FOLIO='3',FILE='C:\JMS\105933\13-20374-2\task6249785\20374-2-ba.htm',USER='105933',CD='Sep 14 02:32 2013' -->

<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 align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">EXHIBIT&nbsp;INDEX</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="12%" valign="bottom" style="border:none;border-bottom:solid windowtext 1.0pt;padding:0in 0in 0in 0in;width:12.08%;">
<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 0in 0in 0in;width:2.5%;">
<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="85%" valign="bottom" style="border:none;border-bottom:solid windowtext 1.0pt;padding:0in 0in 0in 0in;width:85.42%;">
<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><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="12%" valign="top" style="border:none;padding:0in 0in 0in 0in;width:12.08%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">1.1</font></p>    </td>
<td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.5%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="85%" valign="top" style="border:none;padding:0in 0in 0in 0in;width:85.42%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Underwriting   Agreement, dated September&nbsp;9, 2013, by and among Corporate Office   Properties Trust, Corporate Office Properties, L.P. and Wells Fargo   Securities, LLC, Barclays Capital Inc. and Citigroup Global Markets Inc., as   representatives of the several underwriters named therein</font></p>    </td>   </tr>
<tr>
<td width="12%" valign="top" style="padding:0in 0in 0in 0in;width:12.08%;">
<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 0in 0in 0in;width:2.5%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="85%" valign="top" style="padding:0in 0in 0in 0in;width:85.42%;">
<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="12%" valign="top" style="padding:0in 0in 0in 0in;width:12.08%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">4.1</font></p>    </td>
<td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.5%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="85%" valign="top" style="padding:0in 0in 0in 0in;width:85.42%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Form&nbsp;of   Global Note Representing $250,000,000 Aggregate Principal Amount of 5.25%   Senior Notes due 2024</font></p>    </td>   </tr>
<tr>
<td width="12%" valign="top" style="padding:0in 0in 0in 0in;width:12.08%;">
<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 0in 0in 0in;width:2.5%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="85%" valign="top" style="padding:0in 0in 0in 0in;width:85.42%;">
<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="12%" valign="top" style="padding:0in 0in 0in 0in;width:12.08%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">4.2</font></p>    </td>
<td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.5%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="85%" valign="top" style="padding:0in 0in 0in 0in;width:85.42%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Form&nbsp;of   First Supplemental Indenture, by and among Corporate Office Properties, L.P.,   as issuer, Corporate Office Properties Trust, as guarantor, and U.S. Bank   National Association, as trustee</font></p>    </td>   </tr>
<tr>
<td width="12%" valign="top" style="padding:0in 0in 0in 0in;width:12.08%;">
<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 0in 0in 0in;width:2.5%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="85%" valign="top" style="padding:0in 0in 0in 0in;width:85.42%;">
<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="12%" valign="top" style="padding:0in 0in 0in 0in;width:12.08%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">5.1</font></p>    </td>
<td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.5%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="85%" valign="top" style="padding:0in 0in 0in 0in;width:85.42%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Opinion   of Saul Ewing LLP regarding the validity of the Notes</font></p>    </td>   </tr>
<tr>
<td width="12%" valign="top" style="padding:0in 0in 0in 0in;width:12.08%;">
<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 0in 0in 0in;width:2.5%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="85%" valign="top" style="padding:0in 0in 0in 0in;width:85.42%;">
<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="12%" valign="top" style="padding:0in 0in 0in 0in;width:12.08%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">5.2</font></p>    </td>
<td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.5%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="85%" valign="top" style="padding:0in 0in 0in 0in;width:85.42%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Opinion   of Morgan, Lewis&nbsp;&amp; Bockius LLP regarding the validity of the Notes</font></p>    </td>   </tr>
<tr>
<td width="12%" valign="top" style="padding:0in 0in 0in 0in;width:12.08%;">
<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 0in 0in 0in;width:2.5%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="85%" valign="top" style="padding:0in 0in 0in 0in;width:85.42%;">
<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="12%" valign="top" style="padding:0in 0in 0in 0in;width:12.08%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">8.1</font></p>    </td>
<td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.5%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="85%" valign="top" style="padding:0in 0in 0in 0in;width:85.42%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Opinion   of Morgan, Lewis &amp; Bockius LLP</font></p>    </td>   </tr>
<tr>
<td width="12%" valign="top" style="padding:0in 0in 0in 0in;width:12.08%;">
<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 0in 0in 0in;width:2.5%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="85%" valign="top" style="padding:0in 0in 0in 0in;width:85.42%;">
<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="12%" valign="top" style="padding:0in 0in 0in 0in;width:12.08%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">23.1</font></p>    </td>
<td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.5%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="85%" valign="top" style="padding:0in 0in 0in 0in;width:85.42%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Consent   of Saul Ewing LLP (contained in Exhibit 5.1)</font></p>    </td>   </tr>
<tr>
<td width="12%" valign="top" style="padding:0in 0in 0in 0in;width:12.08%;">
<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 0in 0in 0in;width:2.5%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="85%" valign="top" style="padding:0in 0in 0in 0in;width:85.42%;">
<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="12%" valign="top" style="padding:0in 0in 0in 0in;width:12.08%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">23.2</font></p>    </td>
<td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.5%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="85%" valign="top" style="padding:0in 0in 0in 0in;width:85.42%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Consent   of Morgan, Lewis &amp; Bockius LLP (contained in Exhibit 5.2)</font></p>    </td>   </tr>
<tr>
<td width="12%" valign="top" style="padding:0in 0in 0in 0in;width:12.08%;">
<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 0in 0in 0in;width:2.5%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="85%" valign="top" style="padding:0in 0in 0in 0in;width:85.42%;">
<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="12%" valign="top" style="padding:0in 0in 0in 0in;width:12.08%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">23.3</font></p>    </td>
<td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.5%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="85%" valign="top" style="padding:0in 0in 0in 0in;width:85.42%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Consent   of Morgan, Lewis &amp; Bockius LLP (contained in Exhibit 8.1)</font></p>    </td>   </tr>  </table>
<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;">4<a name="PB_4_111011_3020"></a></font></p>
<div style="margin:0in 0in .0001pt;"><hr size="3" width="100%" noshade color="#010101" align="left"></div>
</div>
<!-- SEQ.=1,FOLIO='4',FILE='C:\JMS\105933\13-20374-2\task6249785\20374-2-ba.htm',USER='105933',CD='Sep 14 02:32 2013' -->

</body>
</html>
[{"type": "8-K", "sequence": "1", "filename": "a13-20374_28k.htm", "description": "8-K", "secsgml_size_bytes": 67285}]
[{"company-data": {"conformed-name": "Corporate Office Properties, L.P.", "cik": "0001577966", "assigned-sic": "6798", "irs-number": "232930022", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "8-K", "act": "34", "file-number": "333-189188", "film-number": "131097076"}, "business-address": {"street1": "6711 COLUMBIA GATEWAY DRIVE", "street2": "SUITE 300", "city": "COLUMBIA", "state": "MD", "zip": "21046", "phone": "443-285-5400"}, "mail-address": {"street1": "6711 COLUMBIA GATEWAY DRIVE", "street2": "SUITE 300", "city": "COLUMBIA", "state": "MD", "zip": "21046"}}, {"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": "131097077"}, "business-address": {"street1": "6711 COLUMBIA GATEWAY DRIVE", "street2": "SUITE 300", "city": "COLUMBIA", "state": "MD", "zip": "21046", "phone": "4432855400"}, "mail-address": {"street1": "6711 COLUMBIA GATEWAY DRIVE", "street2": "SUITE 300", "city": "COLUMBIA", "state": "MD", "zip": "21046"}, "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"}]}]
–
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)
September 9, 2013
CORPORATE OFFICE PROPERTIES TRUST
CORPORATE OFFICE PROPERTIES, L.P.
(Exact name of registrant as specified in its charter)
Corporate Office Properties Trust
Maryland
1-14023
23-2947217
(State or other jurisdiction of
(Commission File
(IRS Employer
incorporation or organization)
Number)
Identification No.)
Corporate Office Properties, L.P.
Delaware
333-189188
23-2930022
(State or other jurisdiction of
(Commission File
(IRS Employer
incorporation or organization)
Number)
Identification No.)
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 8.01              Other Events
On September 9, 2013, Corporate Office Properties, L.P. (the "Operating Partnership"), the operating partnership of Corporate Office Properties Trust (the "Company"), priced a public offering (the "Offering") of $250 million aggregate principal amount of its 5.25% Senior Notes due 2024 (the "Notes").  In connection with the Offering, the Company and the Operating Partnership entered into an Underwriting Agreement with Wells Fargo Securities, LLC, Barclays Capital Inc. and Citigroup Global Markets Inc., as representatives of the several underwriters named therein, that provides for the issuance and sale of the Notes by the Operating Partnership.  The offering of the Notes is registered under the Securities Act of 1933, as amended, pursuant to the Registration Statement on Form S-3 (File No. 333-190137) filed by the Company and the Operating Partnership with the Securities and Exchange Commission (the "Commission) on July 25, 2013 (the "Registration Statement").  The terms of the Notes, which will be issued on September 16, 2013, will be governed by a senior indenture, to be dated September 16, 2013, by and among the Operating Partnership, as issuer, the Company, as guarantor, and U.S. Bank National Association, as trustee (the "Base Indenture"), as supplemented and amended by a supplemental indenture thereto, to be dated September 16, 2013 (the "First Supplemental Indenture," and together with the Base Indenture, the "Indenture").
A copy of the form of Base Indenture was previously filed as Exhibit 4.1 to the Registration Statement and is incorporated by reference herein.  Copies of the Underwriting Agreement, the form of Global Note and the form of First Supplemental Indenture are filed as Exhibits 1.1, 4.1 and 4.2 hereto, respectively, and are incorporated by reference herein.  The summaries of the Underwriting Agreement, the Notes and the Indenture in this Current Report on Form 8-K do not purport to be complete and are qualified in their entirety by reference to Exhibits 1.1, 4.1 and 4.2 to this Current Report on Form 8-K.
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
Exhibit Title
1.1
Underwriting   Agreement, dated September 9, 2013, by and among Corporate Office   Properties Trust, Corporate Office Properties, L.P. and Wells Fargo   Securities, LLC, Barclays Capital Inc. and Citigroup Global Markets Inc., as   representatives of the several underwriters named therein
4.1
Form of   Global Note Representing $250,000,000 Aggregate Principal Amount of 5.25%   Senior Notes due 2024
4.2
Form of   First Supplemental Indenture, by and among Corporate Office Properties, L.P.,   as issuer, Corporate Office Properties Trust, as guarantor, and U.S. Bank   National Association, as trustee
5.1
Opinion   of Saul Ewing LLP regarding the validity of the Notes
5.2
Opinion   of Morgan, Lewis & Bockius LLP regarding the validity of the Notes
8.1
Opinion   of Morgan, Lewis & Bockius LLP
23.1
Consent   of Saul Ewing LLP (contained in Exhibit 5.1)
23.2
Consent   of Morgan, Lewis & Bockius LLP (contained in Exhibit 5.2)
23.3
Consent   of Morgan, Lewis & Bockius LLP (contained in Exhibit 8.1)
2
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.
CORPORATE OFFICE PROPERTIES TRUST
CORPORATE   OFFICE PROPERTIES, L.P.
By:   Corporate Office Properties Trust,
its   General Partner
/s/ Stephen E. Riffee
/s/   Stephen E. Riffee
Stephen E. Riffee
Stephen   E. Riffee
Executive Vice President and Chief Financial   Officer
Executive   Vice President and Chief Financial Officer
Dated:
September 13,   2013
Dated:
September 13,   2013
3
EXHIBIT INDEX
Exhibit Number
Exhibit Title
1.1
Underwriting   Agreement, dated September 9, 2013, by and among Corporate Office   Properties Trust, Corporate Office Properties, L.P. and Wells Fargo   Securities, LLC, Barclays Capital Inc. and Citigroup Global Markets Inc., as   representatives of the several underwriters named therein
4.1
Form of   Global Note Representing $250,000,000 Aggregate Principal Amount of 5.25%   Senior Notes due 2024
4.2
Form of   First Supplemental Indenture, by and among Corporate Office Properties, L.P.,   as issuer, Corporate Office Properties Trust, as guarantor, and U.S. Bank   National Association, as trustee
5.1
Opinion   of Saul Ewing LLP regarding the validity of the Notes
5.2
Opinion   of Morgan, Lewis & Bockius LLP regarding the validity of the Notes
8.1
Opinion   of Morgan, Lewis & Bockius LLP
23.1
Consent   of Saul Ewing LLP (contained in Exhibit 5.1)
23.2
Consent   of Morgan, Lewis & Bockius LLP (contained in Exhibit 5.2)
23.3
Consent   of Morgan, Lewis & Bockius LLP (contained in Exhibit 8.1)
4