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<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="5" face="Times New Roman" style="font-size:18.0pt;font-weight:bold;">UNITED STATES<br> SECURITIES AND EXCHANGE COMMISSION</font></b></p>
<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">WASHINGTON, D.C.&#160; 20549</font></b></p>
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<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="5" face="Times New Roman" style="font-size:18.0pt;font-weight:bold;">FORM&nbsp;8-K</font></b></p>
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<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;"><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 the Securities Exchange Act of 1934</font></b></p>
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<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)&#160; <b>May&nbsp;16, 2013</b></font></p>
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<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="5" face="Times New Roman" style="font-size:18.0pt;font-weight:bold;">TC PipeLines, LP</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>
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<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>
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<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;">001-35358</font></b></p>    </td>
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<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;">52-2135448</font></b></p>    </td>   </tr>
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<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 <br>   of incorporation)</font></p>    </td>
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<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 <br>   Number)</font></p>    </td>
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<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(IRS Employer<br> &nbsp;Identification No.)</font></p>    </td>   </tr>  </table>
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<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;">717 Texas Street, Suite&nbsp;2400<br>   Houston, TX</font></b></p>    </td>
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<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;"><br>   77002-2761</font></b></p>    </td>   </tr>
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<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>    </td>
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<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(Zip Code)</font></p>    </td>   </tr>  </table>
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<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&nbsp;&nbsp;<b>(877) 290-2772</b></font></p>
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<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(Former name or former address if changed since last report)</font></p>
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<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</font></p>
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<p style="margin:0in 0in .0001pt .25in;text-indent:-.25in;"><font size="2" face="Wingdings" style="font-size:10.0pt;">o</font><font size="1" style="font-size:3.0pt;">&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; </font><font size="2" style="font-size:10.0pt;">Written communications pursuant to Rule&nbsp;425 under the Securities Act (17 CFR 230.425)</font></p>
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<p style="margin:0in 0in .0001pt .25in;text-indent:-.25in;"><font size="2" face="Wingdings" style="font-size:10.0pt;">o</font><font size="1" style="font-size:3.0pt;">&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; </font><font size="2" style="font-size:10.0pt;">Soliciting material pursuant to Rule&nbsp;14a-12 under the Exchange Act (17 CFR 240.14a-12)</font></p>
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<p style="margin:0in 0in .0001pt .25in;text-indent:-.25in;"><font size="2" face="Wingdings" style="font-size:10.0pt;">o</font><font size="1" style="font-size:3.0pt;">&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; </font><font size="2" style="font-size:10.0pt;">Pre-commencement communications pursuant to Rule&nbsp;14d-2(b)&nbsp;under the Exchange Act (17 CFR 240.14d-2(b))</font></p>
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
<p style="margin:0in 0in .0001pt .25in;text-indent:-.25in;"><font size="2" face="Wingdings" style="font-size:10.0pt;">o</font><font size="1" style="font-size:3.0pt;">&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; </font><font size="2" 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>
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<p style="margin:0in 0in .0001pt;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">Item 1.01&#160; <u>Entry into a Material Definitive Agreement</u></font></b><font size="2" style="font-size:10.0pt;">.</font></p>
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<p style="margin:0in 0in .0001pt;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">On May&nbsp;16, 2013, TC PipeLines, LP (the &#147;Partnership&#148;) entered into an Underwriting Agreement (the &#147;Underwriting Agreement&#148;) with Wells Fargo Securities, LLC, Merrill Lynch, Pierce, Fenner&nbsp;&amp; Smith Incorporated, J.P. Morgan Securities LLC, Morgan Stanley&nbsp;&amp; Co. LLC, UBS Securities LLC, Deutsche Bank Securities Inc. and RBC Capital Markets, LLC (the &#147;Underwriters&#148;), that provides for the issuance and sale by the Partnership, and the purchase by the Underwriters, of 7,700,000 common units representing limited partner interests in the Partnership. The Underwriters were also granted an option&nbsp;to purchase an additional 1,155,000 common units on the same terms and conditions. The material terms of the offering of the common units are described in the prospectus supplement, dated May&nbsp;16, 2013, filed by the Partnership with the Securities and Exchange Commission (the &#147;Commission&#148;).&nbsp; The offer and sale of the common units are registered with the Commission under the Securities Act of 1933, as amended, pursuant to a shelf registration statement on Form&nbsp;S-3 (File No.&nbsp;333-188628).&nbsp; The Partnership expects the transaction to close on Wednesday, May&nbsp;22, 2013, subject to customary closing conditions.</font></p>
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<p style="margin:0in 0in .0001pt;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">The Underwriting Agreement contains customary representations, warranties and agreements of the Partnership and certain affiliates, and customary conditions to closing, indemnification rights, obligations of the parties and termination provisions.</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;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">The foregoing description of the Underwriting Agreement is qualified in its entirety by reference to such Underwriting Agreement, a copy of which is filed herewith as Exhibit&nbsp;1.1 and is incorporated herein by reference.</font></p>
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<p style="margin:0in 0in .0001pt;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">Item 7.01&#160; <u>Regulation FD Disclosure.</u></font></b></p>
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<p style="margin:0in 0in .0001pt;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">On May&nbsp;16, 2013, the Partnership issued a press release announcing that it had priced the offering described in Item 1.01 of this Current Report on Form&nbsp;8-K. A copy of the press release is furnished as Exhibit&nbsp;99.1 hereto.</font></p>
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<p style="margin:0in 0in .0001pt;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">Item 9.01&#160; <u>Financial Statements and Exhibits</u>.</font></b></p>
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<p style="margin:0in 0in .0001pt .4in;text-indent:-.4in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(d)&#160;&#160;&#160;&#160;&#160;&#160;&#160; <u>Exhibits</u>.</font></p>
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<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">1.1</font></p>    </td>
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<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Underwriting   Agreement, dated May&nbsp;16, 2013, among TC PipeLines, LP, TC PipeLines   GP,&nbsp;Inc. and </font><font size="2" style="font-size:10.0pt;">Wells Fargo Securities,   LLC, Merrill Lynch, Pierce, Fenner&nbsp;&amp; Smith Incorporated, J.P. Morgan   Securities LLC, Morgan Stanley&nbsp;&amp; Co. LLC, UBS Securities LLC,   Deutsche Bank Securities Inc. and RBC Capital Markets, LLC</font><font size="2" style="font-size:10.0pt;">.</font></p>    </td>   </tr>
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<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Opinion   of Orrick, Herrington&nbsp;&amp; Sutcliffe LLP.</font></p>    </td>   </tr>  </table>
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<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_081707_7056"></a></font></p>
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<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Opinion   of Orrick, Herrington&nbsp;&amp; Sutcliffe LLP with respect to tax matters.</font></p>    </td>   </tr>
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<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="88%" valign="top" style="padding:0in 0in 0in 0in;width:88.88%;">
<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="8%" valign="top" style="padding:0in 0in 0in 0in;width:8.88%;">
<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:2.24%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="88%" valign="top" style="padding:0in 0in 0in 0in;width:88.88%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Consent   of Orrick, Herrington&nbsp;&amp; Sutcliffe LLP (included in Exhibits 5.1 and   8.1).</font></p>    </td>   </tr>
<tr>
<td width="8%" valign="top" style="padding:0in 0in 0in 0in;width:8.88%;">
<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:2.24%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="88%" valign="top" style="padding:0in 0in 0in 0in;width:88.88%;">
<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="8%" valign="top" style="padding:0in 0in 0in 0in;width:8.88%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">99.1</font></p>    </td>
<td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.24%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="88%" valign="top" style="padding:0in 0in 0in 0in;width:88.88%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Press   Release of TC PipeLines, LP, dated May&nbsp;16, 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_081735_5335"></a></font></p>
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<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">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;"><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>
<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="48%" valign="top" style="padding:0in 0in 0in 0in;width:48.36%;">
<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="51%" colspan="2" valign="top" style="padding:0in 0in 0in 0in;width:51.64%;">
<p style="margin:0in 0in .0001pt;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">TC   PipeLines, LP</font></b><font size="2" style="font-size:10.0pt;">  </font></p>    </td>   </tr>
<tr>
<td width="48%" valign="top" style="padding:0in 0in 0in 0in;width:48.36%;">
<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="51%" colspan="2" valign="top" style="padding:0in 0in 0in 0in;width:51.64%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">by:   TC PipeLines GP,&nbsp;Inc., </font></p>    </td>   </tr>
<tr>
<td width="48%" valign="top" style="padding:0in 0in 0in 0in;width:48.36%;">
<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="51%" colspan="2" valign="top" style="padding:0in 0in 0in 0in;width:51.64%;">
<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>
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<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="51%" colspan="2" valign="top" style="padding:0in 0in 0in 0in;width:51.64%;">
<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>   </tr>
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<td width="48%" valign="top" style="padding:0in 0in 0in 0in;width:48.36%;">
<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>
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<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>   </tr>
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<td width="48%" valign="top" style="padding:0in 0in 0in 0in;width:48.36%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="3%" valign="top" style="padding:0in 0in 0in 0in;width:3.88%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">By:   </font></p>    </td>
<td width="47%" valign="top" style="border:none;border-bottom:solid windowtext 1.0pt;padding:0in 0in 0in 0in;width:47.78%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">/s/   Annie C. Belecki </font></p>    </td>   </tr>
<tr>
<td width="48%" valign="top" style="padding:0in 0in 0in 0in;width:48.36%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="3%" valign="top" style="padding:0in 0in 0in 0in;width:3.88%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="47%" valign="top" style="border:none;padding:0in 0in 0in 0in;width:47.78%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Annie   C. Belecki </font></p>    </td>   </tr>
<tr>
<td width="48%" valign="top" style="padding:0in 0in 0in 0in;width:48.36%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="3%" valign="top" style="padding:0in 0in 0in 0in;width:3.88%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="47%" valign="top" style="padding:0in 0in 0in 0in;width:47.78%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Secretary</font></p>    </td>   </tr>  </table>
<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;">&nbsp;</font></p>
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Dated:&#160; May&nbsp;17, 2013</font></p>
<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">4<a name="PB_4_082047_5796"></a></font></p>
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<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">EXHIBIT&nbsp;INDEX</font></b></p>
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
<table border="0" cellspacing="0" cellpadding="0" width="100%" style="border-collapse:collapse;width:100.0%;">
<tr>
<td width="8%" valign="bottom" style="border:none;border-bottom:solid windowtext 1.0pt;padding:0in 0in 0in 0in;width:8.88%;">
<p style="margin:0in 0in .0001pt;"><b><font size="1" face="Times New Roman" style="font-size:8.0pt;font-weight:bold;">Exhibit&nbsp;No.</font></b></p>    </td>
<td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.24%;">
<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="88%" valign="bottom" style="border:none;border-bottom:solid windowtext 1.0pt;padding:0in 0in 0in 0in;width:88.88%;">
<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;">Description</font></b></p>    </td>   </tr>
<tr>
<td width="8%" valign="top" style="border:none;padding:0in 0in 0in 0in;width:8.88%;">
<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="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.24%;">
<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="88%" valign="top" style="border:none;padding:0in 0in 0in 0in;width:88.88%;">
<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>   </tr>
<tr>
<td width="8%" valign="top" style="padding:0in 0in 0in 0in;width:8.88%;">
<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:2.24%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="88%" valign="top" style="padding:0in 0in 0in 0in;width:88.88%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Underwriting   Agreement, dated May&nbsp;16, 2013, among TC PipeLines, LP, TC PipeLines   GP,&nbsp;Inc. and</font><font size="2" style="font-size:10.0pt;"> Wells Fargo   Securities, LLC, Merrill Lynch, Pierce, Fenner&nbsp;&amp; Smith Incorporated,   J.P. Morgan Securities LLC, Morgan Stanley&nbsp;&amp; Co. LLC, UBS Securities   LLC, Deutsche Bank Securities Inc. and RBC Capital Markets, LLC</font><font size="2" style="font-size:10.0pt;">.</font></p>    </td>   </tr>
<tr>
<td width="8%" valign="top" style="padding:0in 0in 0in 0in;width:8.88%;">
<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:2.24%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="88%" valign="top" style="padding:0in 0in 0in 0in;width:88.88%;">
<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="8%" valign="top" style="padding:0in 0in 0in 0in;width:8.88%;">
<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:2.24%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="88%" valign="top" style="padding:0in 0in 0in 0in;width:88.88%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Opinion   of Orrick, Herrington&nbsp;&amp; Sutcliffe LLP.</font></p>    </td>   </tr>
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<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:2.24%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="88%" valign="top" style="padding:0in 0in 0in 0in;width:88.88%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>   </tr>
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<td width="8%" valign="top" style="padding:0in 0in 0in 0in;width:8.88%;">
<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:2.24%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="88%" valign="top" style="padding:0in 0in 0in 0in;width:88.88%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Opinion   of Orrick, Herrington&nbsp;&amp; Sutcliffe LLP with respect to tax matters.</font></p>    </td>   </tr>
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<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:2.24%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="88%" valign="top" style="padding:0in 0in 0in 0in;width:88.88%;">
<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="8%" valign="top" style="padding:0in 0in 0in 0in;width:8.88%;">
<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:2.24%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="88%" valign="top" style="padding:0in 0in 0in 0in;width:88.88%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Consent   of Orrick, Herrington&nbsp;&amp; Sutcliffe LLP (included in Exhibits 5.1 and   8.1).</font></p>    </td>   </tr>
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<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:2.24%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>    </td>
<td width="88%" valign="top" style="padding:0in 0in 0in 0in;width:88.88%;">
<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="8%" valign="top" style="padding:0in 0in 0in 0in;width:8.88%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">99.1</font></p>    </td>
<td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.24%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>    </td>
<td width="88%" valign="top" style="padding:0in 0in 0in 0in;width:88.88%;">
<p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Press   Release of TC PipeLines, LP, dated May&nbsp;16, 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;">5<a name="PB_5_082122_2897"></a></font></p>
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{"company-data": {"conformed-name": "TC PIPELINES LP", "cik": "0001075607", "assigned-sic": "4922", "irs-number": "522135448", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "8-K", "act": "34", "file-number": "001-35358", "film-number": "13853859"}, "business-address": {"street1": "717 TEXAS STREET, SUITE #2400", "city": "HOUSTON", "state": "TX", "zip": "77002", "phone": "(877) 290-2772"}, "mail-address": {"street1": "717 TEXAS STREET, SUITE #2400", "city": "HOUSTON", "state": "TX", "zip": "77002"}}
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)
May 16, 2013
TC PipeLines, LP
(Exact name of registrant as specified in its charter)
Delaware
001-35358
52-2135448
(State or other jurisdiction
of incorporation)
(Commission File
Number)
(IRS Employer
Identification No.)
717 Texas Street, Suite 2400
Houston, TX
77002-2761
(Address of principal executive offices)
(Zip Code)
Registrant's telephone number, including area code
(877) 290-2772
(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
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 1.01
Entry into a Material Definitive Agreement
.
On May 16, 2013, TC PipeLines, LP (the "Partnership") entered into an Underwriting Agreement (the "Underwriting Agreement") with Wells Fargo Securities, LLC, Merrill Lynch, Pierce, Fenner & Smith Incorporated, J.P. Morgan Securities LLC, Morgan Stanley & Co. LLC, UBS Securities LLC, Deutsche Bank Securities Inc. and RBC Capital Markets, LLC (the "Underwriters"), that provides for the issuance and sale by the Partnership, and the purchase by the Underwriters, of 7,700,000 common units representing limited partner interests in the Partnership. The Underwriters were also granted an option to purchase an additional 1,155,000 common units on the same terms and conditions. The material terms of the offering of the common units are described in the prospectus supplement, dated May 16, 2013, filed by the Partnership with the Securities and Exchange Commission (the "Commission").  The offer and sale of the common units are registered with the Commission under the Securities Act of 1933, as amended, pursuant to a shelf registration statement on Form S-3 (File No. 333-188628).  The Partnership expects the transaction to close on Wednesday, May 22, 2013, subject to customary closing conditions.
The Underwriting Agreement contains customary representations, warranties and agreements of the Partnership and certain affiliates, and customary conditions to closing, indemnification rights, obligations of the parties and termination provisions.
The foregoing description of the Underwriting Agreement is qualified in its entirety by reference to such Underwriting Agreement, a copy of which is filed herewith as Exhibit 1.1 and is incorporated herein by reference.
Item 7.01
Regulation FD Disclosure.
On May 16, 2013, the Partnership issued a press release announcing that it had priced the offering described in Item 1.01 of this Current Report on Form 8-K. A copy of the press release is furnished as Exhibit 99.1 hereto.
Item 9.01
Financial Statements and Exhibits
.
(d)
Exhibits
.
Exhibit No.
Description
1.1
Underwriting   Agreement, dated May 16, 2013, among TC PipeLines, LP, TC PipeLines   GP, Inc. and
Wells Fargo Securities,   LLC, Merrill Lynch, Pierce, Fenner & Smith Incorporated, J.P. Morgan   Securities LLC, Morgan Stanley & Co. LLC, UBS Securities LLC,   Deutsche Bank Securities Inc. and RBC Capital Markets, LLC
.
5.1
Opinion   of Orrick, Herrington & Sutcliffe LLP.
2
8.1
Opinion   of Orrick, Herrington & Sutcliffe LLP with respect to tax matters.
23.1
Consent   of Orrick, Herrington & Sutcliffe LLP (included in Exhibits 5.1 and   8.1).
99.1
Press   Release of TC PipeLines, LP, dated May 16, 2013.
3
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.
TC   PipeLines, LP
by:   TC PipeLines GP, Inc.,
its   general partner
By:
/s/   Annie C. Belecki
Annie   C. Belecki
Secretary
Dated:  May 17, 2013
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EXHIBIT INDEX
Exhibit No.
Description
1.1
Underwriting   Agreement, dated May 16, 2013, among TC PipeLines, LP, TC PipeLines   GP, Inc. and
Wells Fargo   Securities, LLC, Merrill Lynch, Pierce, Fenner & Smith Incorporated,   J.P. Morgan Securities LLC, Morgan Stanley & Co. LLC, UBS Securities   LLC, Deutsche Bank Securities Inc. and RBC Capital Markets, LLC
.
5.1
Opinion   of Orrick, Herrington & Sutcliffe LLP.
8.1
Opinion   of Orrick, Herrington & Sutcliffe LLP with respect to tax matters.
23.1
Consent   of Orrick, Herrington & Sutcliffe LLP (included in Exhibits 5.1 and   8.1).
99.1
Press   Release of TC PipeLines, LP, dated May 16, 2013.
5