-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 VM+3r5RRxJkCZX+orv+i5CT4jRvjaxCuJgQyJkq3vPS4hdE9GAnyQqaJE3aayePE
 Z+239STse9bebwd73l+CmA==

<SEC-DOCUMENT>0001263995-04-000007.txt : 20040929
<SEC-HEADER>0001263995-04-000007.hdr.sgml : 20040929
<ACCEPTANCE-DATETIME>20040929113007
ACCESSION NUMBER:		0001263995-04-000007
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040921
FILED AS OF DATE:		20040929
DATE AS OF CHANGE:		20040929

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Mirosh Walentin
		CENTRAL INDEX KEY:			0001304420

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-26091
		FILM NUMBER:		041051624

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		(403) 750-4848

	MAIL ADDRESS:	
		STREET 1:		PO BOX 2518, STATION M
		CITY:			CALGARY
		STATE:			A0
		ZIP:			T2P 5C6

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			TC PIPELINES LP
		CENTRAL INDEX KEY:			0001075607
		STANDARD INDUSTRIAL CLASSIFICATION:	NATURAL GAS TRANSMISSION [4922]
		IRS NUMBER:				522135448
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		110 TURNPIKE ROAD SUITE 203
		CITY:			WESTBOROUGH
		STATE:			MA
		ZIP:			01581
		BUSINESS PHONE:		5088717046

	MAIL ADDRESS:	
		STREET 1:		110 TURNPIKE RD
		STREET 2:		SUITE 203
		CITY:			WESTBOROUGH
		STATE:			MA
		ZIP:			01581
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2004-09-21</periodOfReport>

    <noSecuritiesOwned>1</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001075607</issuerCik>
        <issuerName>TC PIPELINES LP</issuerName>
        <issuerTradingSymbol>TCLP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001304420</rptOwnerCik>
            <rptOwnerName>Mirosh Walentin</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>PO BOX 2518, STATION M</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>CALGARY</rptOwnerCity>
            <rptOwnerState>A0</rptOwnerState>
            <rptOwnerZipCode>T2P 5C6</rptOwnerZipCode>
            <rptOwnerStateDescription>ALBERTA, CANADA</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <ownerSignature>
        <signatureName>/s/Maryse C. St. Laurent, Attorney for Walentin Mirosh</signatureName>
        <signatureDate>2004-09-29</signatureDate>
    </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----