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<P style="MARGIN-TOP: 4px; MARGIN-BOTTOM: 0px" align=center><FONT style="FONT-FAMILY: Times New Roman" size=5><B>UNITED STATES </B></FONT></P>

<P style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px" align=center><FONT style="FONT-FAMILY: Times New Roman" size=5><B>SECURITIES AND EXCHANGE COMMISSION </B></FONT></P>

<P style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px" align=center><FONT style="FONT-FAMILY: Times New Roman" size=3><B>Washington, D.C. 20549 </B></FONT></P>

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<P style="MARGIN-TOP: 12px; MARGIN-BOTTOM: 0px" align=center><FONT STYLE="font: large Times New Roman"><B>FORM 8-K</B></FONT></P>

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<P style="MARGIN-TOP: 12px; MARGIN-BOTTOM: 0px" align=center><FONT style="FONT-FAMILY: Times New Roman" size=4><B>CURRENT REPORT </B></FONT></P>

<P style="MARGIN-TOP: 12px; MARGIN-BOTTOM: 0px" align=center><B><FONT style="FONT-SIZE: 11pt">Pursuant to Section&nbsp;13 or 15(d) of </FONT></B></P>

<P style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px" align=center><FONT style="FONT-FAMILY: times new roman"><B><FONT style="FONT-SIZE: 11pt">The Securities Exchange Act of 1934</FONT></B></FONT></P>

<P style="MARGIN-TOP: 12px; MARGIN-BOTTOM: 0px" align=center><FONT style="FONT-FAMILY: times new roman"><B>Date of
Report (Date of earliest event reported): <FONT style="FONT-SIZE: 11pt" face="Times New Roman">December 12,
2013</FONT></B></FONT></P>

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   <TD width="60%"><FONT style="FONT-SIZE: 22pt"><STRONG><FONT style="FONT-FAMILY: arial; FONT-SIZE: 16pt">Performance Technologies,</FONT></STRONG><FONT style="FONT-FAMILY: arial; FONT-SIZE: 16pt"> </FONT></FONT></TD></TR>

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   <TD width="56%"><FONT style="FONT-FAMILY: Times New Roman" size=6><B><FONT style="FONT-FAMILY: arial; FONT-SIZE: 16pt">Incorporated</FONT><FONT style="FONT-FAMILY: arial; FONT-SIZE: 16pt">&nbsp;</FONT></B></FONT></TD></TR></TABLE>
<Center><FONT style="FONT-FAMILY: Times New Roman" size=2><B>(Exact name of registrant as specified in its charter) </B></FONT></center></P>

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   <TD vAlign=top align=center><FONT style="FONT-FAMILY: Times New Roman" size=2><B>Delaware</B></FONT></TD>

   <TD vAlign=bottom><FONT size=1>&nbsp;</FONT></TD>

   <TD vAlign=bottom align=center><FONT style="FONT-FAMILY: Times New Roman" size=2><B>0-27460</B></FONT></TD>

   <TD vAlign=bottom><FONT size=1>&nbsp;</FONT></TD>

   <TD vAlign=bottom align=center><FONT style="FONT-FAMILY: Times New Roman" size=2><B>16-1158413</B></FONT></TD></TR>

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   <P style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px" align=center><FONT style="FONT-FAMILY: Times New Roman" size=1><B>(State or other jurisdiction</B></FONT></P>

   <P style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 1px" align=center><FONT style="FONT-FAMILY: Times New Roman" size=1><B>of incorporation)</B></FONT></P></TD>

   <TD vAlign=bottom><FONT size=1>&nbsp;</FONT></TD>

   <TD vAlign=top align=center><FONT style="FONT-FAMILY: Times New Roman" size=1><B>(Commission File Number)</B></FONT></TD>

   <TD vAlign=bottom><FONT size=1>&nbsp;</FONT></TD>

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   <P style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px" align=center><FONT style="FONT-FAMILY: Times New Roman" size=1><B>(I.R.S. Employer</B></FONT></P>

   <P style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 1px" align=center><FONT style="FONT-FAMILY: Times New Roman" size=1><B>Identification No.)</B></FONT></P></TD></TR>

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   <TD vAlign=top colSpan=3 align=center><FONT style="FONT-FAMILY: Times New Roman" size=2><B>140 Canal View Boulevard&nbsp;&nbsp; Rochester, New York</B></FONT></TD>

   <TD vAlign=bottom><FONT size=1>&nbsp;</FONT></TD>

   <TD vAlign=bottom align=center><FONT style="FONT-FAMILY: Times New Roman" size=2><B>14623</B></FONT></TD></TR>

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   <TD vAlign=top colSpan=3 align=center><FONT style="FONT-FAMILY: Times New Roman" size=1><B>(Address of&nbsp;principal&nbsp;executive offices)</B></FONT></TD>

   <TD vAlign=bottom><FONT size=1>&nbsp;</FONT></TD>

   <TD vAlign=bottom align=center><FONT style="FONT-FAMILY: Times New Roman" size=1><B>(Zip Code)</B></FONT></TD></TR></TABLE>

<P style="MARGIN-TOP: 12px; MARGIN-BOTTOM: 0px" align=center><FONT style="FONT-FAMILY: Times New Roman" size=2><B>Registrant&#8217;s telephone number, including area code: (585)&nbsp;256-0200</B></FONT></P>

<P style="MARGIN-TOP: 24px; MARGIN-BOTTOM: 0px" align=center><FONT style="FONT-FAMILY: Times New Roman" size=1><B>(Former name or former address, if changed since last report.) </B></FONT></P>

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<P style="MARGIN-TOP: 12px; MARGIN-BOTTOM: 0px"><FONT style="FONT-FAMILY: Times New Roman" size=2>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: </FONT></P>

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   <TD vAlign=top width="4%" align=left><FONT style="FONT-FAMILY: Times New Roman" size=2><FONT style="FONT-FAMILY: WINGDINGS">&#168;</FONT></FONT></TD>

   <TD vAlign=top align=left><FONT style="FONT-FAMILY: Times New Roman" size=2>Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) </FONT></TD></TR></TABLE>

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   <TD vAlign=top width="4%" align=left><FONT style="FONT-FAMILY: Times New Roman" size=2><FONT style="FONT-FAMILY: WINGDINGS">&#254;</FONT></FONT></TD>

   <TD vAlign=top align=left><FONT style="FONT-FAMILY: Times New Roman" size=2>Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) </FONT></TD></TR></TABLE>

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   <TD vAlign=top width="4%" align=left><FONT style="FONT-FAMILY: Times New Roman" size=2><FONT style="FONT-FAMILY: WINGDINGS">&#168;</FONT></FONT></TD>

   <TD vAlign=top align=left><FONT style="FONT-FAMILY: Times New Roman" size=2>Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) </FONT></TD></TR></TABLE>

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   <TD vAlign=top width="4%" align=left><FONT style="FONT-FAMILY: Times New Roman" size=2><FONT style="FONT-FAMILY: WINGDINGS">&#168;</FONT></FONT></TD>

   <TD vAlign=top align=left><FONT style="FONT-FAMILY: Times New Roman" size=2>Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) </FONT></TD></TR></TABLE>

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<P STYLE="font: 11pt/115% Times New Roman, Times, Serif; margin: 0 0 10pt">&nbsp;</P>

<P STYLE="font: bold 12pt Times New Roman, Times, Serif; margin: 0 0 11pt"><FONT STYLE="font-size: 10pt">Item&nbsp;1.01. Entry
into a Material Definitive Agreement.</FONT></P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0 0 12pt; text-indent: 0.5in"><FONT STYLE="font-size: 10pt">On December
12, 2013, Performance Technologies, Incorporated (the &ldquo;Company&rdquo;) entered into an Agreement and Plan of Merger (the
&ldquo;Merger Agreement&rdquo;) with Sonus Networks, Inc. (&ldquo;Sonus&rdquo;), and Purple Acquisition Subsidiary, Inc. a wholly-owned
subsidiary of Sonus (&ldquo;Merger Sub&rdquo;).</FONT></P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0 0 12pt; text-indent: 0.5in"><FONT STYLE="font-size: 10pt">Pursuant
to the terms of the Merger Agreement, Merger Sub will merge with and into the Company with the Company surviving and becoming
a wholly-owned subsidiary of Sonus (the &ldquo;Merger&rdquo;). At the effective time of the Merger (the &ldquo;Effective Time&rdquo;),
each share of the Company&rsquo;s common stock, par value $0.01 per share, issued and outstanding immediately prior to the Effective
Time will be converted automatically into the right to receive $3.75 in cash.</FONT></P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0"><FONT STYLE="font-size: 10pt">In addition, at the Effective Time
of the Merger, Sonus will assume all of the then outstanding stock options under the Company&rsquo;s 2001 Stock Option Plan, 2003
Omnibus Incentive Plan and 2012 Omnibus Incentive Plan (the &ldquo;Assumed Options&rdquo;), but will substitute shares of Sonus&rsquo;s
common stock for shares of the Company&rsquo;s common stock issuable upon exercise thereof and adjust the exercise price of the
Assumed Options based on a formula set forth in the Merger Agreement. Sonus will also assume the Company&rsquo;s 2003 Omnibus
Incentive Plan and 2012 Omnibus Incentive Plan, but will substitute shares of Sonus&rsquo;s common stock for shares of the Company&rsquo;s
common stock. Certain of the Assumed Options that were issued to the Company&rsquo;s executive officers and directors contain
a provision that will accelerate vesting upon a change in control that will be triggered by the Merger. &nbsp;Vesting of all other
Assumed Options will not change as a result of the Merger and each Assumed Option will continue to vest pursuant to its vesting
schedule in effect immediately prior to the Effective Time of the Merger.&nbsp;</FONT></P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0 0 12pt; text-indent: 0.5in"><FONT STYLE="font-size: 10pt">Consummation
of the Merger is subject to customary conditions, including (i) the approval by the holders of a majority of the outstanding shares
of the Company&rsquo;s common stock entitled to vote on the Merger (the &ldquo;Stockholder Approval&rdquo;) and (ii) the absence
of any injunction, judgment or ruling prohibiting the Merger. Moreover, each party&rsquo;s obligation to consummate the Merger
is subject to certain other conditions, including (i) the accuracy of the other party&rsquo;s representations and warranties (subject
to materiality exceptions) and (ii) the other party&rsquo;s compliance with its covenants and agreements contained in the Merger
Agreement (subject to materiality exceptions). If the Merger is not consummated by June 30, 2014, either Sonus or the Company
may terminate the Merger Agreement. The consummation of the Merger is not subject to a financing condition.</FONT></P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0 0 12pt; text-indent: 0.5in"><FONT STYLE="font-size: 10pt">The Company
has made customary representations and warranties and covenants in the Merger Agreement, including covenants regarding: (i) the
conduct of the business of the Company prior to the consummation of the Merger and (ii) the calling and holding of a meeting of
the Company&rsquo;s stockholders for the purpose of obtaining the Stockholder Approval.</FONT></P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0 0 12pt; text-indent: 0.5in"><FONT STYLE="font-size: 10pt">The Company
is subject to customary &ldquo;no-shop&rdquo; restrictions on its ability to solicit alternative acquisition proposals from third
parties and to provide information to and participate in discussions and engage in negotiations with third parties regarding alternative
acquisition proposals. However, prior to approval of the Merger by the Company&rsquo;s stockholders, the no-shop provision is
subject to customary exceptions for the Company to respond to and support unsolicited proposals in the exercise of the fiduciary
duties of its board of directors.</FONT></P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0 0 12pt; text-indent: 0.5in"><FONT STYLE="font-size: 10pt">The Merger
Agreement contains certain termination rights for Sonus and the Company. Upon termination of the Merger Agreement under specified
circumstances, the Company will be required to pay Sonus a termination fee of $1.2 million, including if the Company terminates
the Merger Agreement in accordance with its terms to accept an unsolicited superior proposal.</FONT></P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0 0 12pt; text-indent: 0.5in"><FONT STYLE="font-size: 10pt">In connection
with the Merger Agreement, John M. Slusser, the Chairman of the Board of Directors and President and Chief Executive Officer of
the Company, executed a Voting Agreement with Sonus (the &ldquo;Voting Agreement&rdquo;) solely in his capacity as a stockholder,
and not as a director or officer of the Company. The Voting Agreement (a) requires the stockholder to vote in favor of (and to
grant a proxy to Sonus to vote in favor of) the Merger and adoption of the Merger Agreement, and to vote against the approval
or adoption of any proposal that is in opposition to or in competition with the Merger Agreement and (b) prohibits the applicable
stockholder from transferring such stockholder&rsquo;s shares of the Company common stock prior to the occurrence of the Company
stockholders&rsquo; meeting to be held in connection with the Merger, subject to certain exceptions.</FONT></P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0 0 12pt; text-indent: 0.5in"><FONT STYLE="font-size: 10pt">The foregoing
descriptions of the Merger Agreement and the Voting Agreement and the transactions contemplated thereby do not purport to be complete
and are subject to, and qualified in their entirety by, the full text of the Merger Agreement attached hereto as Exhibit 2.1 and
the full text of the Voting Agreement attached hereto as Exhibit 10.1, which are incorporated herein by reference.</FONT></P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0 0 12pt; text-indent: 0.5in"><FONT STYLE="font-size: 10pt">The Merger
Agreement and Voting Agreement have been attached as exhibits to provide investors with information regarding their terms. They
are not intended to provide any other factual information about Sonus, the Company or Merger Sub. The representations, warranties
and covenants contained in the Merger Agreement and Voting Agreement were made solely for the purposes of the Merger Agreement
and Voting Agreement and the benefit of the parties thereto, and may be subject to limitations agreed upon by the contracting
parties. Certain of the representations and warranties have been made for the purposes of allocating contractual risk between
the parties instead of establishing these matters as facts. In addition, the representations and warranties contained in the Merger
Agreement (i)&nbsp;are qualified by information in a confidential disclosure schedule that the parties have exchanged, (ii)&nbsp;were
made only as of the dates specified in the Merger Agreement or the confidential disclosure schedule, and (iii)&nbsp;in some cases
are subject to qualifications with respect to materiality, knowledge and/or other matters, including standards of materiality
applicable to the contracting parties that differ from those applicable to investors. Moreover, information concerning the subject
matter of the representations and warranties may change after the date of the Merger Agreement and Voting Agreements, which subsequent
information may or may not be fully reflected in the Company public disclosures. Accordingly, investors should not rely on the
representations and warranties as characterizations of the actual state of facts or condition of the Company or any of its subsidiaries
or affiliates.</FONT></P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0 0 2pt; text-indent: 0.5in"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0 0 12pt 1in; text-indent: -1in"><FONT STYLE="font-size: 10pt"><B>Item
5.02.&#9;Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Company Arrangements
of Certain Officers.</B></FONT></P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0 0 12pt; text-indent: 0.5in"><FONT STYLE="font-size: 10pt">Pursuant
to the Merger Agreement, the Company will make the following payments at the Effective Time to the Company&rsquo;s named executive
officers if they are still employed by the Company at the Effective Time:</FONT></P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0"><FONT STYLE="font-size: 10pt">John M. Slusser &#9;&nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;$168,550</FONT></P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0"><FONT STYLE="font-size: 10pt">Dorrance W. Lamb &#9;&nbsp;&nbsp;&nbsp;$121,941</FONT></P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0"><FONT STYLE="font-size: 10pt">J. Patrick Rice
&#9;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;$107,015</FONT></P>

<P STYLE="font: bold 11pt Times New Roman, Times, Serif; margin: 0 0 12pt"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></P>

<P STYLE="font: bold 11pt Times New Roman, Times, Serif; margin: 0 0 12pt"><FONT STYLE="font-size: 10pt">Item 8.01.&#9;Other Events.</FONT></P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0 0 12pt; text-indent: 0.5in"><FONT STYLE="font-size: 10pt">On December
13, 2013, the Company and Sonus issued a press release in connection with the Merger. A copy of the press release is attached
hereto as Exhibit 99.1.</FONT></P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0 0 0pt; text-indent: 0.5in"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></P>

<P STYLE="font: bold 11pt Times New Roman, Times, Serif; margin: 0 0 12pt"><FONT STYLE="font-size: 10pt">Item 9.01.&#9;Financial
Statements and Exhibits.</FONT></P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0 0 12pt; text-indent: 0.5in"><FONT STYLE="font-size: 10pt">(d)&#9;Exhibits:</FONT></P>

<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="font: 11pt Times New Roman, Times, Serif; width: 100%; border-collapse: collapse">
<TR STYLE="vertical-align: top">
    <TD NOWRAP STYLE="padding-right: 5.4pt; padding-left: 5.4pt"><P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0; border-bottom: black 0.75pt solid"><FONT STYLE="font-size: 10pt"><B>Exhibit&nbsp;No.</B></FONT></P></TD>
    <TD STYLE="padding-right: 5.4pt; padding-left: 5.4pt"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD>
    <TD STYLE="padding-right: 5.4pt; padding-left: 5.4pt"><P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0; border-bottom: black 0.75pt solid"><FONT STYLE="font-size: 10pt"><B>Description</B></FONT></P></TD></TR>
<TR STYLE="vertical-align: top">
    <TD STYLE="padding-right: 5.4pt; padding-left: 5.4pt"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD>
    <TD COLSPAN="2" STYLE="padding-right: 5.4pt; padding-left: 5.4pt"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD></TR>
<TR STYLE="vertical-align: top">
    <TD NOWRAP STYLE="padding-right: 4pt; padding-left: 5.4pt; text-align: center"><FONT STYLE="font-size: 10pt">2.1</FONT></TD>
    <TD STYLE="padding-right: 5.4pt; padding-left: 5.4pt"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD>
    <TD STYLE="padding-right: 5.4pt; padding-left: 5.4pt"><P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0"><FONT STYLE="font-size: 10pt">Agreement and Plan of Merger,
        dated as of December 12, 2013, by and among Sonus, the Company and Merger Sub. Schedules and exhibits have been omitted
        pursuant to Item 601(b)(2) of Regulation S-K. The Registrant hereby undertakes to furnish copies of any of the omitted
        schedules and exhibits upon request by the U.S. Securities and Exchange Commission.</FONT></P>
        <P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></P></TD></TR>
<TR STYLE="vertical-align: top">
    <TD NOWRAP STYLE="padding-right: 4pt; padding-left: 5.4pt; text-align: center"><FONT STYLE="font-size: 10pt">10.1</FONT></TD>
    <TD STYLE="padding-right: 5.4pt; padding-left: 5.4pt"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD>
    <TD STYLE="padding-right: 5.4pt; padding-left: 5.4pt"><FONT STYLE="font-size: 10pt">Stockholder Voting Agreement, dated as
    of December 12, 2013, by and between Sonus and John M. Slusser.</FONT></TD></TR>
<TR STYLE="vertical-align: top">
    <TD NOWRAP STYLE="padding-right: 4pt; padding-left: 5.4pt; text-align: right"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD>
    <TD STYLE="padding-right: 5.4pt; padding-left: 5.4pt"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD>
    <TD STYLE="padding-right: 5.4pt; padding-left: 5.4pt"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD></TR>
<TR STYLE="vertical-align: top">
    <TD NOWRAP STYLE="padding-right: 4pt; padding-left: 5.4pt; text-align: center"><FONT STYLE="font-size: 10pt">99.1</FONT></TD>
    <TD STYLE="padding-right: 5.4pt; padding-left: 5.4pt"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD>
    <TD STYLE="padding-right: 5.4pt; padding-left: 5.4pt"><FONT STYLE="font-size: 10pt">Joint Press Release.</FONT></TD></TR>
</TABLE>
<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 3.5pt 0 0"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 13.5pt 0 0"><FONT STYLE="font-size: 10pt"><B>Additional Information
About the Merger and Where to Find It </B></FONT></P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 4.5pt 0 0"><FONT STYLE="font-size: 10pt">In connection with the proposed
merger, the Company plans to file a proxy statement with the Securities and Exchange Commission (the &ldquo;SEC&rdquo;). Additionally,
the Company and Sonus will file other relevant materials in connection with the proposed acquisition of the Company by Sonus pursuant
to the terms of the Merger Agreement by and among the Company, Sonus and Merger Sub. The definitive proxy statement will be sent
to stockholders of the Company and will contain important information about the Company, Sonus, the proposed merger and related
matters. Investors and security holders of the Company are urged to read the definitive proxy statement and other relevant materials
carefully, when they become available, before making any voting or investment decision with respect to the proposed merger because
they will contain important information about the merger and the parties to the merger.</FONT></P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 9pt 0 0"><FONT STYLE="font-size: 10pt">The Company and Sonus, and
their respective directors, executive officers, and other members of their management and employees, under SEC rules, may be deemed
to be participants in the solicitation of proxies of the Company stockholders in connection with the transactions contemplated
by the Merger Agreement. Information regarding Sonus&rsquo; directors and executive officers is contained in Sonus&rsquo; Annual
Report on Form 10-K for the year ended December 31, 2012 and its proxy statement dated April 25, 2013, and other relevant materials
filed with the SEC when they become available. Investors and security holders may obtain detailed information regarding the names,
affiliations and interests of certain of the Company&rsquo;s executive officers and directors in the solicitation by reading the
Company&rsquo;s most recent Annual Report on Form 10-K for the year ended December 31, 2012, its proxy statement dated April 22,
2013, and other relevant materials filed with the SEC when they become available. Information concerning the interests of the
Company&rsquo;s participants in the solicitation, which may, in some cases, be different from those of the Company&rsquo;s stockholders,
will be set forth in the proxy statement relating to the merger when it becomes available.</FONT></P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 9pt 0 0"><FONT STYLE="font-size: 10pt">&nbsp;The materials to be filed
by the Company with the SEC may be obtained free of charge at the SEC&rsquo;s website at www.sec.gov. In addition, security holders
will be able to obtain free copies of the proxy statement from the Company by contacting Investor Relations by e-mail at finance@pt.com
or by telephone at 585-256-0200, ext. 7276.</FONT></P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 9pt 0 0"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0 0 12pt"><FONT STYLE="font-size: 10pt"><B>Forward-Looking Statements</B></FONT></P>

<P STYLE="margin: 0"><FONT STYLE="font-size: 10pt">The Private Securities Litigation Reform Act of 1995 provides a &quot;safe
harbor&quot; for certain forward-looking statements. This press release contains forward-looking statements which reflect the
Company's current views with respect to future events and financial performance, within the meaning of Section 27A of the Securities
Act of 1933 and Section 21E of the Securities Exchange Act of 1934 and is subject to the safe harbor provisions of those sections.
The Company&rsquo;s future operating results are subject to various risks and uncertainties and could differ materially from those
discussed in the forward-looking statements and may be affected by various trends and factors which are beyond the Company&rsquo;s
control. These risks and uncertainties include, among other factors, the Company&rsquo;s ability to close the Merger, uncertainty
as to the timing and results of the Stockholder Approval, the effect of disruption from the Merger, difficulty in maintaining
relationships with its employees, customers, vendors, business partners or government entities as a result of the Merger, the
impact of the Merger on the sale of the Company&rsquo;s products and services, business and economic conditions, rapid technological
changes accompanied by frequent new product introductions, competitive pressures, dependence on key customers and the potential
loss of key customers, inability to gauge order flows from customers, fluctuations in quarterly and annual results, the reliance
on a limited number of third party suppliers, limitations of the Company&rsquo;s manufacturing capacity and arrangements, the
protection of the Company&rsquo;s proprietary technology, errors or defects in our products, the effects of pending or threatened
litigation, the dependence on key personnel, changes in critical accounting estimates, potential impairments related to investments,
foreign regulations, possible loss or significant curtailment of significant government contracts or subcontracts, possible effects
related to compliance with new conflict-free mineral regulations, and potential material weaknesses in internal control over financial
reporting. In addition, during weak or uncertain economic periods, customers&rsquo; visibility deteriorates causing delays in
the placement of their orders. These factors often result in a substantial portion of the Company&rsquo;s revenue being derived
from orders placed within a quarter and shipped in the final month of the same quarter. Forward-looking statements should be read
in conjunction with the most recent audited Consolidated Financial Statements, the Notes thereto, Risk Factors, and Management's
Discussion and Analysis of Financial Condition and Results of Operations of the Company, as contained in the Company&rsquo;s Annual
Report on Form 10-K, and other documents filed with the Securities and Exchange Commission.</FONT></P>



<P STYLE="font: bold 12pt Times New Roman, Times, Serif; margin: 0 0 11pt"></P>



<P STYLE="font: 11pt/115% Times New Roman, Times, Serif; margin: 0 0 10pt"></P>


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    <DIV STYLE="page-break-before: always; margin-top: 6pt"><TABLE CELLPADDING="0" CELLSPACING="0" STYLE="width: 100%"><TR><TD STYLE="text-align: center; width: 100%">&nbsp;</TD></TR></TABLE></DIV>
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<P STYLE="font: bold 11pt Times New Roman, Times, Serif; margin: 0 0 12pt; text-align: center"></P>

<P STYLE="font: bold 11pt Times New Roman, Times, Serif; margin: 0 0 12pt; text-align: center"><FONT STYLE="font-size: 10pt">SIGNATURES</FONT></P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0 0 12pt; text-indent: 0.5in"><FONT STYLE="font-size: 10pt">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="font: 11pt Times New Roman, Times, Serif; margin: 0 0 12pt"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></P>

<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="width: 100%; border-collapse: collapse">
<TR STYLE="vertical-align: top">
    <TD STYLE="width: 38%; font: 11pt Times New Roman, Times, Serif; padding-right: 5.4pt; padding-left: 5.4pt"><FONT STYLE="font-size: 10pt"><B>&nbsp;</B></FONT></TD>
    <TD STYLE="width: 62%; padding-right: 5.4pt; padding-left: 5.4pt"><P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0"><FONT STYLE="font-size: 10pt"><B>Performance
                                                                      Technologies, Incorporated</B></FONT></P>
        <P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></P></TD></TR>
<TR STYLE="vertical-align: top">
    <TD STYLE="font: 11pt Times New Roman, Times, Serif; padding-right: 5.4pt; padding-left: 5.4pt"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD>
    <TD STYLE="font: 11pt Times New Roman, Times, Serif; padding-right: 5.4pt; padding-left: 5.4pt"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD></TR>
<TR STYLE="vertical-align: top">
    <TD STYLE="font: 11pt Times New Roman, Times, Serif; padding-right: 5.4pt; padding-left: 5.4pt"><FONT STYLE="font-size: 10pt">Date:&nbsp;&nbsp;December
    13, 2013</FONT></TD>
    <TD STYLE="font: 11pt Times New Roman, Times, Serif; padding-right: 5.4pt; padding-left: 5.4pt"><FONT STYLE="font-size: 10pt">By:
    <U>/s/ John M. Slusser&#9;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#9;</U></FONT></TD></TR>
<TR STYLE="vertical-align: top">
    <TD STYLE="font: 11pt Times New Roman, Times, Serif; padding-right: 5.4pt; padding-left: 5.4pt"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD>
    <TD STYLE="padding-right: 5.4pt; padding-left: 5.4pt"><P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0"><FONT STYLE="font-size: 10pt">John
                                                          M. Slusser</FONT></P>
        <P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0"><FONT STYLE="font-size: 10pt">President and Chief Executive
        Officer</FONT></P></TD></TR>
<TR STYLE="vertical-align: top">
    <TD STYLE="font: 11pt Times New Roman, Times, Serif; padding-right: 5.4pt; padding-left: 5.4pt"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD>
    <TD STYLE="font: 11pt Times New Roman, Times, Serif; padding-right: 5.4pt; padding-left: 5.4pt"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD></TR>
<TR STYLE="vertical-align: top">
    <TD STYLE="font: 11pt Times New Roman, Times, Serif; padding-right: 5.4pt; padding-left: 5.4pt"><FONT STYLE="font-size: 10pt">Date:&nbsp;&nbsp;December
    13, 2013</FONT></TD>
    <TD STYLE="font: 11pt Times New Roman, Times, Serif; padding-right: 5.4pt; padding-left: 5.4pt"><FONT STYLE="font-size: 10pt">By:
    <U>/s/ Dorrance W. Lamb &nbsp;&nbsp;&nbsp;&nbsp;&#9;</U></FONT></TD></TR>
<TR STYLE="vertical-align: top">
    <TD STYLE="font: 11pt Times New Roman, Times, Serif; padding-right: 5.4pt; padding-left: 5.4pt"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD>
    <TD STYLE="padding-right: 5.4pt; padding-left: 5.4pt"><P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0"><FONT STYLE="font-size: 10pt">Dorrance
                                                          W. Lamb</FONT></P>
        <P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0"><FONT STYLE="font-size: 10pt">Senior Vice President Finance
        and Chief Financial Officer</FONT></P></TD></TR>
<TR STYLE="vertical-align: top">
    <TD STYLE="font: 11pt Times New Roman, Times, Serif; padding-right: 5.4pt; padding-left: 5.4pt"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD>
    <TD STYLE="font: 11pt Times New Roman, Times, Serif; padding-right: 5.4pt; padding-left: 5.4pt"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD></TR>
</TABLE>

<P STYLE="font: bold 11pt Times New Roman, Times, Serif; margin: 0 0 12pt; text-align: center"></P>

<P STYLE="font: bold 11pt Times New Roman, Times, Serif; margin: 0 0 12pt; text-align: center"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></P>


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    <DIV STYLE="page-break-before: always; margin-top: 6pt"><TABLE CELLPADDING="0" CELLSPACING="0" STYLE="width: 100%"><TR><TD STYLE="text-align: center; width: 100%">&nbsp;</TD></TR></TABLE></DIV>
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<P STYLE="font: bold 11pt Times New Roman, Times, Serif; margin: 0 0 12pt; text-align: center"><FONT STYLE="font-size: 10pt">EXHIBIT
INDEX</FONT></P>

<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="width: 100%; border-collapse: collapse">
<TR STYLE="vertical-align: top">
    <TD NOWRAP STYLE="padding-right: 5.4pt; padding-left: 5.4pt"><P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0; border-bottom: black 0.75pt solid"><FONT STYLE="font-size: 10pt"><B>Exhibit&nbsp;No.</B></FONT></P></TD>
    <TD STYLE="padding-right: 5.4pt; padding-bottom: 10pt; padding-left: 5.4pt; font: 11pt/115% Calibri, Helvetica, Sans-Serif"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD>
    <TD STYLE="padding-right: 5.4pt; padding-left: 5.4pt"><P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0; border-bottom: black 0.75pt solid"><FONT STYLE="font-size: 10pt"><B>Description</B></FONT></P></TD></TR>
<TR STYLE="vertical-align: top">
    <TD STYLE="padding-right: 5.4pt; padding-bottom: 10pt; padding-left: 5.4pt; font: 11pt/115% Calibri, Helvetica, Sans-Serif"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD>
    <TD COLSPAN="2" STYLE="padding-right: 5.4pt; padding-bottom: 10pt; padding-left: 5.4pt; font: 11pt/115% Calibri, Helvetica, Sans-Serif"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD></TR>
<TR STYLE="vertical-align: top">
    <TD NOWRAP STYLE="padding-right: 4pt; padding-bottom: 10pt; padding-left: 5.4pt; font: 11pt/115% Calibri, Helvetica, Sans-Serif; text-align: center"><FONT STYLE="font: 10pt Times New Roman, Times, Serif">2.1</FONT></TD>
    <TD STYLE="padding-right: 5.4pt; padding-bottom: 10pt; padding-left: 5.4pt; font: 11pt/115% Calibri, Helvetica, Sans-Serif"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD>
    <TD STYLE="padding-right: 5.4pt; padding-left: 5.4pt"><P STYLE="font: 11pt/115% Times New Roman, Times, Serif; margin: 0 0 10pt"><FONT STYLE="font-size: 10pt">Agreement and
        Plan of Merger, dated as of December 12, 2013, by and among Sonus, the Company and Merger Sub. Schedules and exhibits
        have been omitted pursuant to Item 601(b)(2) of Regulation S-K. The Registrant hereby undertakes to furnish copies of
        any of the omitted schedules and exhibits upon request by the U.S. Securities and Exchange Commission.&nbsp;&nbsp;</FONT></P></TD></TR>
<TR STYLE="vertical-align: top">
    <TD NOWRAP STYLE="padding-right: 4pt; padding-bottom: 10pt; padding-left: 5.4pt; font: 11pt/115% Calibri, Helvetica, Sans-Serif; text-align: center"><FONT STYLE="font: 10pt Times New Roman, Times, Serif">10.1</FONT></TD>
    <TD STYLE="padding-right: 5.4pt; padding-bottom: 10pt; padding-left: 5.4pt; font: 11pt/115% Calibri, Helvetica, Sans-Serif"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD>
    <TD STYLE="padding-right: 5.4pt; padding-bottom: 10pt; padding-left: 5.4pt; font: 11pt/115% Calibri, Helvetica, Sans-Serif"><FONT STYLE="font: 10pt Times New Roman, Times, Serif">Stockholder
    Voting Agreement, dated as of December 12, 2013, by and between Sonus and John M. Slusser.</FONT></TD></TR>
<TR STYLE="vertical-align: top">
    <TD NOWRAP STYLE="padding-right: 4pt; padding-bottom: 10pt; padding-left: 5.4pt; font: 11pt/115% Calibri, Helvetica, Sans-Serif; text-align: center"><FONT STYLE="font: 10pt Times New Roman, Times, Serif">99.1</FONT></TD>
    <TD STYLE="padding-right: 5.4pt; padding-bottom: 10pt; padding-left: 5.4pt; font: 11pt/115% Calibri, Helvetica, Sans-Serif"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD>
    <TD STYLE="padding-right: 5.4pt; padding-bottom: 10pt; padding-left: 5.4pt; font: 11pt/115% Calibri, Helvetica, Sans-Serif"><FONT STYLE="font: 10pt Times New Roman, Times, Serif">Joint
    Press Release.</FONT></TD></TR>
</TABLE>
<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0 0 12pt"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></P>

<P STYLE="font: 11pt/115% Times New Roman, Times, Serif; margin: 0 0 10pt"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></P>



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{"company-data": {"conformed-name": "PERFORMANCE TECHNOLOGIES INC \\DE\\", "cik": "0001003950", "assigned-sic": "3576", "irs-number": "161158413", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "8-K", "act": "34", "file-number": "000-27460", "film-number": "131275077"}, "business-address": {"street1": "140 CANAL VIEW BOULEVARD", "city": "ROCHESTER", "state": "NY", "zip": "14623", "phone": "5852560200"}, "mail-address": {"street1": "140 CANAL VIEW BOULEVARD", "city": "ROCHESTER", "state": "NY", "zip": "14623"}}
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 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):
December 12,
2013
Performance Technologies,
Incorporated
(Exact name of registrant as specified in its charter)
Delaware
0-27460
16-1158413
(State or other jurisdiction
of incorporation)
(Commission File Number)
(I.R.S. Employer
Identification No.)
140 Canal View Boulevard   Rochester, New York
14623
(Address of principal executive offices)
(Zip Code)
Registrant's telephone number, including area code: (585) 256-0200
(Former name or former address, if changed since last report.)
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:
¨
Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
þ
Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
¨
Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
¨
Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))
Item 1.01. Entry
into a Material Definitive Agreement.
On December
12, 2013, Performance Technologies, Incorporated (the "Company") entered into an Agreement and Plan of Merger (the
"Merger Agreement") with Sonus Networks, Inc. ("Sonus"), and Purple Acquisition Subsidiary, Inc. a wholly-owned
subsidiary of Sonus ("Merger Sub").
Pursuant
to the terms of the Merger Agreement, Merger Sub will merge with and into the Company with the Company surviving and becoming
a wholly-owned subsidiary of Sonus (the "Merger"). At the effective time of the Merger (the "Effective Time"),
each share of the Company's common stock, par value $0.01 per share, issued and outstanding immediately prior to the Effective
Time will be converted automatically into the right to receive $3.75 in cash.
In addition, at the Effective Time
of the Merger, Sonus will assume all of the then outstanding stock options under the Company's 2001 Stock Option Plan, 2003
Omnibus Incentive Plan and 2012 Omnibus Incentive Plan (the "Assumed Options"), but will substitute shares of Sonus's
common stock for shares of the Company's common stock issuable upon exercise thereof and adjust the exercise price of the
Assumed Options based on a formula set forth in the Merger Agreement. Sonus will also assume the Company's 2003 Omnibus
Incentive Plan and 2012 Omnibus Incentive Plan, but will substitute shares of Sonus's common stock for shares of the Company's
common stock. Certain of the Assumed Options that were issued to the Company's executive officers and directors contain
a provision that will accelerate vesting upon a change in control that will be triggered by the Merger.  Vesting of all other
Assumed Options will not change as a result of the Merger and each Assumed Option will continue to vest pursuant to its vesting
schedule in effect immediately prior to the Effective Time of the Merger.
Consummation
of the Merger is subject to customary conditions, including (i) the approval by the holders of a majority of the outstanding shares
of the Company's common stock entitled to vote on the Merger (the "Stockholder Approval") and (ii) the absence
of any injunction, judgment or ruling prohibiting the Merger. Moreover, each party's obligation to consummate the Merger
is subject to certain other conditions, including (i) the accuracy of the other party's representations and warranties (subject
to materiality exceptions) and (ii) the other party's compliance with its covenants and agreements contained in the Merger
Agreement (subject to materiality exceptions). If the Merger is not consummated by June 30, 2014, either Sonus or the Company
may terminate the Merger Agreement. The consummation of the Merger is not subject to a financing condition.
The Company
has made customary representations and warranties and covenants in the Merger Agreement, including covenants regarding: (i) the
conduct of the business of the Company prior to the consummation of the Merger and (ii) the calling and holding of a meeting of
the Company's stockholders for the purpose of obtaining the Stockholder Approval.
The Company
is subject to customary "no-shop" restrictions on its ability to solicit alternative acquisition proposals from third
parties and to provide information to and participate in discussions and engage in negotiations with third parties regarding alternative
acquisition proposals. However, prior to approval of the Merger by the Company's stockholders, the no-shop provision is
subject to customary exceptions for the Company to respond to and support unsolicited proposals in the exercise of the fiduciary
duties of its board of directors.
The Merger
Agreement contains certain termination rights for Sonus and the Company. Upon termination of the Merger Agreement under specified
circumstances, the Company will be required to pay Sonus a termination fee of $1.2 million, including if the Company terminates
the Merger Agreement in accordance with its terms to accept an unsolicited superior proposal.
In connection
with the Merger Agreement, John M. Slusser, the Chairman of the Board of Directors and President and Chief Executive Officer of
the Company, executed a Voting Agreement with Sonus (the "Voting Agreement") solely in his capacity as a stockholder,
and not as a director or officer of the Company. The Voting Agreement (a) requires the stockholder to vote in favor of (and to
grant a proxy to Sonus to vote in favor of) the Merger and adoption of the Merger Agreement, and to vote against the approval
or adoption of any proposal that is in opposition to or in competition with the Merger Agreement and (b) prohibits the applicable
stockholder from transferring such stockholder's shares of the Company common stock prior to the occurrence of the Company
stockholders' meeting to be held in connection with the Merger, subject to certain exceptions.
The foregoing
descriptions of the Merger Agreement and the Voting Agreement and the transactions contemplated thereby do not purport to be complete
and are subject to, and qualified in their entirety by, the full text of the Merger Agreement attached hereto as Exhibit 2.1 and
the full text of the Voting Agreement attached hereto as Exhibit 10.1, which are incorporated herein by reference.
The Merger
Agreement and Voting Agreement have been attached as exhibits to provide investors with information regarding their terms. They
are not intended to provide any other factual information about Sonus, the Company or Merger Sub. The representations, warranties
and covenants contained in the Merger Agreement and Voting Agreement were made solely for the purposes of the Merger Agreement
and Voting Agreement and the benefit of the parties thereto, and may be subject to limitations agreed upon by the contracting
parties. Certain of the representations and warranties have been made for the purposes of allocating contractual risk between
the parties instead of establishing these matters as facts. In addition, the representations and warranties contained in the Merger
Agreement (i) are qualified by information in a confidential disclosure schedule that the parties have exchanged, (ii) were
made only as of the dates specified in the Merger Agreement or the confidential disclosure schedule, and (iii) in some cases
are subject to qualifications with respect to materiality, knowledge and/or other matters, including standards of materiality
applicable to the contracting parties that differ from those applicable to investors. Moreover, information concerning the subject
matter of the representations and warranties may change after the date of the Merger Agreement and Voting Agreements, which subsequent
information may or may not be fully reflected in the Company public disclosures. Accordingly, investors should not rely on the
representations and warranties as characterizations of the actual state of facts or condition of the Company or any of its subsidiaries
or affiliates.
Item
5.02.	Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Company Arrangements
of Certain Officers.
Pursuant
to the Merger Agreement, the Company will make the following payments at the Effective Time to the Company's named executive
officers if they are still employed by the Company at the Effective Time:
John M. Slusser 	         $168,550
Dorrance W. Lamb 	   $121,941
J. Patrick Rice
	           $107,015
Item 8.01.	Other Events.
On December
13, 2013, the Company and Sonus issued a press release in connection with the Merger. A copy of the press release is attached
hereto as Exhibit 99.1.
Item 9.01.	Financial
Statements and Exhibits.
(d)	Exhibits:
Exhibit No.
Description
2.1
Agreement and Plan of Merger,
        dated as of December 12, 2013, by and among Sonus, the Company and Merger Sub. Schedules and exhibits have been omitted
        pursuant to Item 601(b)(2) of Regulation S-K. The Registrant hereby undertakes to furnish copies of any of the omitted
        schedules and exhibits upon request by the U.S. Securities and Exchange Commission.
10.1
Stockholder Voting Agreement, dated as
    of December 12, 2013, by and between Sonus and John M. Slusser.
99.1
Joint Press Release.
Additional Information
About the Merger and Where to Find It
In connection with the proposed
merger, the Company plans to file a proxy statement with the Securities and Exchange Commission (the "SEC"). Additionally,
the Company and Sonus will file other relevant materials in connection with the proposed acquisition of the Company by Sonus pursuant
to the terms of the Merger Agreement by and among the Company, Sonus and Merger Sub. The definitive proxy statement will be sent
to stockholders of the Company and will contain important information about the Company, Sonus, the proposed merger and related
matters. Investors and security holders of the Company are urged to read the definitive proxy statement and other relevant materials
carefully, when they become available, before making any voting or investment decision with respect to the proposed merger because
they will contain important information about the merger and the parties to the merger.
The Company and Sonus, and
their respective directors, executive officers, and other members of their management and employees, under SEC rules, may be deemed
to be participants in the solicitation of proxies of the Company stockholders in connection with the transactions contemplated
by the Merger Agreement. Information regarding Sonus' directors and executive officers is contained in Sonus' Annual
Report on Form 10-K for the year ended December 31, 2012 and its proxy statement dated April 25, 2013, and other relevant materials
filed with the SEC when they become available. Investors and security holders may obtain detailed information regarding the names,
affiliations and interests of certain of the Company's executive officers and directors in the solicitation by reading the
Company's most recent Annual Report on Form 10-K for the year ended December 31, 2012, its proxy statement dated April 22,
2013, and other relevant materials filed with the SEC when they become available. Information concerning the interests of the
Company's participants in the solicitation, which may, in some cases, be different from those of the Company's stockholders,
will be set forth in the proxy statement relating to the merger when it becomes available.
The materials to be filed
by the Company with the SEC may be obtained free of charge at the SEC's website at www.sec.gov. In addition, security holders
will be able to obtain free copies of the proxy statement from the Company by contacting Investor Relations by e-mail at finance@pt.com
or by telephone at 585-256-0200, ext. 7276.
Forward-Looking Statements
The Private Securities Litigation Reform Act of 1995 provides a "safe
harbor" for certain forward-looking statements. This press release contains forward-looking statements which reflect the
Company's current views with respect to future events and financial performance, within the meaning of Section 27A of the Securities
Act of 1933 and Section 21E of the Securities Exchange Act of 1934 and is subject to the safe harbor provisions of those sections.
The Company's future operating results are subject to various risks and uncertainties and could differ materially from those
discussed in the forward-looking statements and may be affected by various trends and factors which are beyond the Company's
control. These risks and uncertainties include, among other factors, the Company's ability to close the Merger, uncertainty
as to the timing and results of the Stockholder Approval, the effect of disruption from the Merger, difficulty in maintaining
relationships with its employees, customers, vendors, business partners or government entities as a result of the Merger, the
impact of the Merger on the sale of the Company's products and services, business and economic conditions, rapid technological
changes accompanied by frequent new product introductions, competitive pressures, dependence on key customers and the potential
loss of key customers, inability to gauge order flows from customers, fluctuations in quarterly and annual results, the reliance
on a limited number of third party suppliers, limitations of the Company's manufacturing capacity and arrangements, the
protection of the Company's proprietary technology, errors or defects in our products, the effects of pending or threatened
litigation, the dependence on key personnel, changes in critical accounting estimates, potential impairments related to investments,
foreign regulations, possible loss or significant curtailment of significant government contracts or subcontracts, possible effects
related to compliance with new conflict-free mineral regulations, and potential material weaknesses in internal control over financial
reporting. In addition, during weak or uncertain economic periods, customers' visibility deteriorates causing delays in
the placement of their orders. These factors often result in a substantial portion of the Company's revenue being derived
from orders placed within a quarter and shipped in the final month of the same quarter. Forward-looking statements should be read
in conjunction with the most recent audited Consolidated Financial Statements, the Notes thereto, Risk Factors, and Management's
Discussion and Analysis of Financial Condition and Results of Operations of the Company, as contained in the Company's Annual
Report on Form 10-K, and other documents filed with the Securities and Exchange Commission.
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.
Performance
                                                                      Technologies, Incorporated
Date:  December
    13, 2013
By:
/s/ John M. Slusser
John
                                                          M. Slusser
President and Chief Executive
        Officer
Date:  December
    13, 2013
By:
/s/ Dorrance W. Lamb
Dorrance
                                                          W. Lamb
Senior Vice President Finance
        and Chief Financial Officer
EXHIBIT
INDEX
Exhibit No.
Description
2.1
Agreement and
        Plan of Merger, dated as of December 12, 2013, by and among Sonus, the Company and Merger Sub. Schedules and exhibits
        have been omitted pursuant to Item 601(b)(2) of Regulation S-K. The Registrant hereby undertakes to furnish copies of
        any of the omitted schedules and exhibits upon request by the U.S. Securities and Exchange Commission.
10.1
Stockholder
    Voting Agreement, dated as of December 12, 2013, by and between Sonus and John M. Slusser.
99.1
Joint
    Press Release.