UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934*

(Amendment No.    )

TC PIPELINES, LP

(Name of Issuer)

Common Units Representing Limited Partner Interests

(Title of Class of Securities)

87233Q108

(CUSIP Number)

Anthony Merhige

Harvest Fund Advisors LLC

100 West Lancaster Avenue, Suite 200

Wayne, Pennsylvania 19087

Tel: (610) 341-9700

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

October 26, 2020

(Date of Event which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box:  ☐

NOTE: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See Rule 240.13d-7 for other parties to whom copies are to be sent.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

Item 1. Security and Issuer.

This Statement on Schedule 13D (this “Schedule 13D”) relates to common units representing limited partner interests (the “Common Units”) of TC PipeLines, LP, a Delaware limited partnership. The principal executive offices of the Issuer are located at 700 Louisiana Street, Suite 700, Houston, Texas 77002.

Item 2. Identity and Background

(a)-(b) Each of the following is hereinafter individually referred to as a “Reporting Person” and collectively as the “Reporting Persons”. This statement is filed on behalf of:

The principal business address of HFA is 100 W. Lancaster Avenue, Suite 200, Wayne, PA 19087. The principal business address of each of the Blackstone Persons is c/o The Blackstone Group Inc., 345 Park Avenue, New York, New York 10154.

Information regarding each director and executive officer of The Blackstone Group Inc. is set forth on Schedule I attached hereto.

(c) HFA is a registered investment adviser that provides investment management services to funds and separately managed accounts.

The principal business of Harvest Fund Holdco L.P. is performing the functions of, and serving as, the sole member of HFA. The principal business of Blackstone Harvest Holdco L.L.C. is performing the functions of, and serving as, the general partner of Harvest Fund Holdco L.P. The principal business of Blackstone Intermediary Holdco L.L.C. is performing the functions of, and serving as, the sole member of Blackstone Harvest Holdco L.L.C. The principal business of Blackstone Advisory Partners L.P. is performing the functions of, and serving as, the sole member of Blackstone Intermediary Holdco L.L.C. The principal business of Blackstone Advisory Services L.L.C. is performing the functions of, and serving as, the general partner of Blackstone Advisory Partners L.P. The principal business of Blackstone Holdings I L.P. is performing the function of, and serving as, the sole member (or similar position) of Blackstone Advisory Services L.L.C. and other affiliated Blackstone entities. The principal business of Blackstone Holdings I/II GP L.L.C. is performing the functions of, and serving as, the general partner of Blackstone Holdings I L.P. and other affiliated Blackstone entities.

The principal business of The Blackstone Group Inc. is performing the functions of, and serving as, the sole member of Blackstone Holdings I/II GP L.L.C., and in a similar capacity for other affiliated Blackstone entities. The principal business of Blackstone Group Management L.L.C. is performing the functions of, and serving as, the sole holder of Class C common stock of The Blackstone Group Inc.

The principal occupation of Mr. Schwarzman is serving as an executive of The Blackstone Group Inc. and Blackstone Group Management L.L.C.

(d) During the last five years, none of the Reporting Persons or, to the best knowledge of the Reporting Persons, any of the other persons set forth on Schedule I attached hereto, has been convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors).

(e) During the last five years, none of the Reporting Persons or, to the best knowledge of the Reporting Persons, any of the other persons set forth on Schedule I attached hereto, has been a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and, as a result of such proceeding, was or is subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws.

(f) See Items 2(a)-(b) above for place of organization or citizenship of each of the Reporting Persons.

Item 3. Source and Amount of Funds or Other Consideration

The funds and accounts managed by HFA acquired the securities reported herein for aggregate consideration of approximately $127,737,615, using cash available in such funds and accounts.

Item 4. Purpose of Transaction.

HFA acquired the securities reported herein for investment purposes.

The Reporting Persons intend to review their investment in the Issuer on an ongoing basis and, in the course of their review, may take actions (including through their affiliates) with respect to their investment or the Issuer, including communicating with the board of directors of the general partner of the Issuer (the “Board”), members of management or other security-holders of the Issuer, or other third parties from time to time, taking steps to implement a course of action, including, without limitation, engaging advisors, including legal, financial, regulatory, technical and/or industry advisors, to assist in any review, and evaluating strategic alternatives as they may become available. Such discussions and other actions may relate to the proposed acquisition by TC Energy Corporation to acquire all Common Units of the Issuer not currently held by it and its affiliates (the “TC Energy Proposal”), and any other various alternative courses of action, including, without limitation, those related to any other extraordinary corporate transaction (including, but not limited to a merger, reorganization or liquidation) involving the Issuer or any of its subsidiaries; business combinations involving the Issuer or any of its subsidiaries, a sale or transfer of a material amount of assets of the Issuer or any of its subsidiaries; material asset purchases; the formation of joint ventures with the Issuer or any of its subsidiaries or the entry into other material projects; changes in the present business, operations, strategy, future plans or prospects of the Issuer, financial or governance matters; changes to the Board (including board composition) or management of the Issuer; acting as a participant in debt financings of the Issuer or any of its subsidiaries, changes to the capitalization, ownership structure, dividend policy, business or corporate structure or governance documents of the Issuer; de-listing or de-registration of the Issuer’s securities, or any action similar to those enumerated above.

Such discussions and actions may be preliminary and exploratory in nature, and not rise to the level of a plan or proposal. The Reporting Persons or their affiliates may seek to acquire securities of the Issuer, including Common Units and/or other equity, debt, notes or other financial instruments related to the Issuer or the Common Units (which may include rights or securities exercisable or convertible into securities of the Issuer), and/or sell or otherwise dispose of some or all of such Issuer securities or financial instruments (which may include distributing some or all of such securities to such Reporting Person’s respective partners or beneficiaries, as applicable) from time to time, in each case, in open market or private transactions, block sales or otherwise. Any transaction that any of the Reporting Persons or their affiliates may pursue may be made at any time and from time to time without prior notice and will depend on a variety of factors, including, without limitation, the price and availability of the Issuer’s securities or other financial instruments, the Reporting Persons’ or such affiliates’ trading and investment strategies, subsequent developments affecting the Issuer, the Issuer’s business and the Issuer’s prospects (including with respect to the TC Energy Proposal), other investment and business opportunities available to such Reporting Persons and their affiliates, general industry and economic conditions, the securities markets in general, tax considerations and other factors deemed relevant by such Reporting Persons and such affiliates.

Except as described in this Schedule 13D, the Reporting Persons do not have any present plans or proposals that relate to or would result in any of the actions described in subparagraphs (a) through (j) of Item 4 of Schedule 13D, although the Reporting Persons, at any time and from time to time, may review, reconsider and change their position and/or change their purpose and/or develop such plans and may seek to influence management or the Board with respect to the business and affairs of the Issuer and may from time to time consider pursuing or proposing such matters with advisors, the Issuer or other persons.

Item 5. Interest in Securities of the Issuer.

(a) and (b). Calculations of the percentage of Common Units beneficially owned assumes that there are a total of 71,306,396 Common Units outstanding as of August 4, 2020, as reported in the Issuer’s Quarterly Report on Form 10-Q filed on August 5, 2020.

The aggregate number and percentage of Common Units beneficially owned by each Reporting Person and, for each Reporting Person, the number of Common Units as to which there is sole power to vote or to direct the vote, shared power to vote or to direct the vote, sole power to dispose or to direct the disposition, or shared power to dispose or to direct the disposition are set forth on rows 7 through 11 and row 13 of the cover pages of this Schedule 13D and are incorporated herein by reference.

The amounts reported herein reflect the number of Common Units held by funds and accounts managed by HFA as of the date hereof.

Harvest Fund Holdco L.P. is the sole member of HFA. Blackstone Harvest Holdco L.L.C. is the general partner of Harvest Fund Holdco L.P. Blackstone Intermediary Holdco L.L.C. is the sole member of Blackstone Harvest Holdco L.L.C. Blackstone Advisory Partners L.P. is the sole member of Blackstone Intermediary Holdco L.L.C. Blackstone Advisory Services L.L.C. is the general partner of Blackstone Advisory Partners L.P. Blackstone Holdings I L.P. is the sole member of Blackstone Advisory Services L.L.C. Blackstone Holdings I/II GP L.L.C. is the general partner of Blackstone Holdings I L.P. The Blackstone Group Inc. is the sole member of Blackstone Holdings I/II GP L.L.C. The sole holder of the Class C common stock of The Blackstone Group Inc. is Blackstone Group Management L.L.C. Blackstone Group Management L.L.C. is wholly-owned by Blackstone’s senior managing directors and controlled by its founder, Stephen A. Schwarzman.

HFA, an investment adviser registered under the Investment Advisers Act of 1940, as amended, advises funds and accounts. In such capacity, HFA has voting authority and dispositive discretion over the securities of the Issuer described in this Schedule 13D that are owned by the funds and accounts advised by it. Except for the purpose of determining beneficial ownership under Section 13(d) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), HFA and the other Reporting Persons each disclaims beneficial ownership of all securities reported as beneficially owned by HFA in this Schedule 13D. None of the Reporting Persons has any pecuniary interest in the securities reported as beneficially owned by HFA in this Schedule 13D, as such term is used for purposes of Section 16 of the Exchange Act. Neither the filing of this Schedule 13D nor any of its contents shall be deemed to constitute an admission that any of the Reporting Persons is the beneficial owner of the securities referred to herein for purposes of Section 13(d) or Section 16 of the Exchange Act or for any other purpose.

Any beneficial ownership of Common Units by any of the persons listed on Schedule I is set forth on Schedule I attached hereto.

(c) Except as set forth in Schedule II of this Schedule 13D, none of the Reporting Persons has effected any transaction in the past 60 days in Common Units.

(d) To the best knowledge of the Reporting Persons, no person other than the Reporting Persons (or the funds or accounts managed by HFA) has the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the securities beneficially owned by the Reporting Persons identified in this Item 5.

(e) Not applicable.

Item 6. Contracts, Arrangements, Understandings or Relationships With Respect to Securities of the Issuer.

An account managed by HFA has entered into notional principal amount derivative agreements (the “Derivative Agreements”) in the form of cash settled swaps with respect to 184,394 Common Units (representing economic exposure to approximately 0.3% of the Common Units). The Derivative Agreements provide such holder with economic results that are comparable to the economic results of ownership but do not provide it with the power to vote or direct the voting or dispose of or direct the disposition of the Common Units that are the subject of the Derivative Agreements (such units, the “Subject Units”). The Reporting Persons disclaim beneficial ownership in the Subject Units. The counterparties to the Derivative Agreements are unaffiliated third party financial institutions.

Item 7. Material to Be Filed as Exhibits.

SIGNATURES

After reasonable inquiry and to the best of its or his knowledge and belief, each of the undersigned certifies that the information set forth in this statement is true, complete and correct.

Dated: November 5, 2020

[TC PipeLines, LP – Schedule 13D]

SCHEDULE I

Executive Officers and Directors of The Blackstone Group Inc.

The name and principal occupation of each director and executive officer of The Blackstone Group Inc. are set forth below. The address for each person listed below is c/o The Blackstone Group Inc., 345 Park Avenue, New York, New York 10154. All executive officers and directors listed are United States citizens other than The Honorable Brian Mulroney, who is a citizen of Canada, and Sir John Antony Hood, who is a citizen of New Zealand.

OFFICERS:

DIRECTORS:

Except as set forth in this Schedule 13D, to the best knowledge of the Reporting Persons, none of the individuals listed above beneficially owns any Common Units.

SCHEDULE II

The below reflects the transactions in Common Units effected by the Reporting Persons during the past 60 days. All transactions occurred in the open market.

EXHIBIT A

JOINT FILING AGREEMENT

Pursuant to and in accordance with the Securities Exchange Act of 1934, as amended, and the rules and regulations thereunder (the “Exchange Act”) the undersigned hereby agree to the joint filing on behalf of each of them of any filing required by such party under Section 13 of the Exchange Act or any rule or regulation thereunder (including any amendment, restatement, supplement, and/or exhibit thereto) with respect to securities of TC PipeLines, LP, a Delaware limited partnership, and further agree to the filing, furnishing, and/or incorporation by reference of this Agreement as an exhibit thereto. Each of them is responsible for the timely filing of such filings and any amendments thereto, and for the completeness and accuracy of the information concerning such person contained therein; but none of them is responsible for the completeness or accuracy of the information concerning the other persons making the filing, unless such person knows or has reason to believe that such information is inaccurate. This Agreement shall remain in full force and effect until revoked by any party hereto in a signed writing provided to each other party hereto, and then only with respect to such revoking party. This Agreement may be executed in any number of counterparts all of which taken together shall constitute one and the same instrument.

Dated: November 5, 2020

[TC PipeLines, LP – Joint Filing Agreement]