SC 13G

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13G

Under the Securities Exchange Act of 1934

(Amendment No.     )*

LONE PINE RESOURCES INC.

(Name of issuer)

Common Stock

(Title of class of securities)

54222A106

(CUSIP number)

December 22, 2011

(Date of event which requires filing of this statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

¨ Rule 13d-1(b)

x Rule 13d-1(c)

¨ Rule 13d-1(d)

* The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page.

The information required in 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).

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

Janice V. Sharry, Esq.

Haynes and Boone, LLP

2323 Victory Avenue, Suite 700

Dallas, Texas 75219-7673

(214) 651-5562

SCHEDULE 13G

CUSIP No. 54222A106 Page 2 of 9 Pages

(1)	Names of reporting persons MSDC Management, L.P.
(2)	Check the appropriate box if a member of a group (see instructions) (a)  ¨        (b)  x
(3)	SEC use only
(4)	Citizenship or place of organization Delaware
Number of shares beneficially owned by each reporting person with:		(5)	Sole voting power 0
		(6)	Shared voting power 4,460,988
		(7)	Sole dispositive power 0
		(8)	Shared dispositive power 4,460,988
(9)	Aggregate amount beneficially owned by each reporting person 4,460,988
(10)	Check if the aggregate amount in Row (9) excludes certain shares (see instructions)    ¨
(11)	Percent of class represented by amount in Row (9) 5.2%
(12)	Type of reporting person (see instructions) PN

SCHEDULE 13G

CUSIP No. 54222A106 Page 3 of 9 Pages

(1)	Names of reporting persons MSD Energy Partners, L.P.
(2)	Check the appropriate box if a member of a group (see instructions) (a)  ¨        (b)  x
(3)	SEC use only
(4)	Citizenship or place of organization Delaware
Number of shares beneficially owned by each reporting person with:		(5)	Sole voting power 0
		(6)	Shared voting power 4,356,097
		(7)	Sole dispositive power 0
		(8)	Shared dispositive power 4,356,097
(9)	Aggregate amount beneficially owned by each reporting person 4,356,097
(10)	Check if the aggregate amount in Row (9) excludes certain shares (see instructions)    ¨
(11)	Percent of class represented by amount in Row (9) 5.1%
(12)	Type of reporting person (see instructions) PN

SCHEDULE 13G

CUSIP No. 54222A106 Page 4 of 9 Pages

(1)	Names of reporting persons MSD Energy Partners (MM), L.P.
(2)	Check the appropriate box if a member of a group (see instructions) (a)  ¨        (b)  x
(3)	SEC use only
(4)	Citizenship or place of organization Cayman Islands
Number of shares beneficially owned by each reporting person with:		(5)	Sole voting power 0
		(6)	Shared voting power 104,891
		(7)	Sole dispositive power 0
		(8)	Shared dispositive power 104,891
(9)	Aggregate amount beneficially owned by each reporting person 104,891
(10)	Check if the aggregate amount in Row (9) excludes certain shares (see instructions)    ¨
(11)	Percent of class represented by amount in Row (9) 0.1%
(12)	Type of reporting person (see instructions) PN

Item 1.

(a) Name of Issuer

LONE PINE RESOURCES INC.

(b) Address of Issuer’s Principal Executive Offices

Suite 2500, 645-7 Avenue SW, Calgary, Alberta, Canada T2P 4G8

Item 2.

(a) Name of Person Filing

This statement is jointly filed by and on behalf of each of MSDC Management, L.P., MSD Energy Partners, L.P. and MSD Energy Partners (MM), L.P. MSD Energy Partners and MSD Energy Partners (MM) are the record and direct beneficial owners of the securities covered by this statement. MSDC Management is the investment manager of, and may be deemed to beneficially own securities owned by, MSD Energy Partners and MSD Energy Partners (MM). MSDC Management (GP), LLC is the general partner of, and may be deemed to beneficially own securities owned by, MSDC Management. Each reporting person declares that neither the filing of this statement nor anything herein shall be construed as an admission that such person is, for the purposes of Section 13(d) or 13(g) of the Act or any other purpose, the beneficial owner of any securities covered by this statement.

(b) Address of Principal Business Office or, if none, Residence

The address of the principal business office of MSDC Management, L.P. and MSD Energy Partners, L.P. is c/o MSDC Management, L.P., 645 Fifth Avenue, 21st Floor, New York, New York 10022. The address of the principal business office of MSD Energy Partners (MM), L.P. is c/o HSBC Trustee (Cayman) Limited, P.O. Box 484, HSBC House, 68 West Bay Road, Grand Cayman KY1-1106, Cayman Islands.

(c) Citizenship

See Item 4 on the cover page(s) hereto.

(d) Title of Class of Securities

Common Stock

(e) CUSIP Number

54222A106

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Item 3. If this statement is filed pursuant to §§240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is:

(a) ¨ A Broker or dealer registered under Section 15 of the Act (15 U.S.C. 78o);

(b) ¨ A Bank as defined in Section 3(a)(6) of the Act (15 U.S.C. 78c);

(c) ¨ An insurance company as defined in Section 3(a)(19) of the Act (15 U.S.C. 78c);

(d) ¨ An investment company registered under Section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);

(e) ¨ An investment adviser in accordance with §240.13d-1(b)(1)(ii)(E);

(f) ¨ An employee benefit plan or endowment fund in accordance with §240.13d- 1(b)(1)(ii)(F);

(g) ¨ A parent holding company or control person in accordance with §240.13d- 1(b)(1)(ii)(G);

(h) ¨ A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);

(i) ¨ A church plan that is excluded from the definition of an investment company under Section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);

(j) ¨ A non-U.S. institution in accordance with §240.13d–1(b)(1)(ii)(J);

(k) ¨ A group, in accordance with §240.13d-1(b)(1)(ii)(K).

Item 4. Ownership.

(a) Amount beneficially owned: See Item 9 on the cover page(s) hereto.

(b) Percent of class: See Item 11 on the cover page(s) hereto.

(c) Number of shares as to which such person has:

(i) Sole power to vote or to direct the vote: See Item 5 on the cover page(s) hereto.

(ii) Shared power to vote or to direct the vote: See Item 6 on the cover page(s) hereto.

(iii) Sole power to dispose or to direct the disposition of: See Item 7 on the cover page(s) hereto.

(iv) Shared power to dispose or to direct the disposition of: See Item 8 on the cover page(s) hereto.

Item 5. Ownership of 5% or Less of a Class.

If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following ¨.

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Item 6. Ownership of More than 5 Percent on Behalf of Another Person

Not Applicable

Item 7. Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.

Not Applicable

Item 8. Identification and Classification of Members of the Group

Not Applicable

Item 9. Notice of Dissolution of Group

Not Applicable

Item 10. Certifications

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect.

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SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Date: January 3, 2012	MSDC MANAGEMENT, L.P.
	By: Its:	MSDC Management (GP), LLC General Partner
	By:	/s/ Marc R. Lisker
	Name:	Marc R. Lisker
	Title:	Managing Director

MSD ENERGY PARTNERS, L.P.
By: Its: By: Its:	MSDC Management, L.P. Investment Manager MSDC Management (GP), LLC General Partner
By:	/s/ Marc R. Lisker
Name:	Marc R. Lisker
Title:	Managing Director

MSD ENERGY PARTNERS (MM), L.P.
By: Its: By: Its:	MSDC Management, L.P. Investment Manager MSDC Management (GP), LLC General Partner
By:	/s/ Marc R. Lisker
Name:	Marc R. Lisker
Title:	Managing Director

EXHIBIT INDEX

Exhibit	Description of Exhibit
99.1	Joint Filing Agreement (filed herewith)

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EX-99.1

EXHIBIT 99.1

JOINT FILING AGREEMENT

January 3, 2012

Pursuant to and in accordance with the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and the rules and regulations thereunder, each party hereto hereby agrees to the joint filing, on behalf of each of them, of any filing required by such party under Section 13 or Section 16 of the Exchange Act or any rule or regulation thereunder (including any amendment, restatement, supplement, and/or exhibit thereto) with the Securities and Exchange Commission (and, if such security is registered on a national securities exchange, also with the exchange), and further agrees to the filing, furnishing, and/or incorporation by reference of this agreement as an exhibit thereto. 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.

IN WITNESS WHEREOF, each party hereto, being duly authorized, has caused this agreement to be executed and effective as of the date first written above.

Date: January 3, 2012	MSDC MANAGEMENT, L.P.
	By:	MSDC Management (GP), LLC
	Its:	General Partner
:	By:	/s/ Marc R. Lisker
	Name:	Marc R. Lisker
	Title:	Managing Director

MSD ENERGY PARTNERS, L.P.
By:	MSDC Management, L.P.
Its:	Investment Manager
By:	MSDC Management (GP), LLC
Its:	General Partner
By:	/s/ Marc R. Lisker
Name:	Marc R. Lisker
Title:	Managing Director

MSD ENERGY PARTNERS (MM), L.P.
By:	MSDC Management, L.P.
Its:	Investment Manager
By:	MSDC Management (GP), LLC
Its:	General Partner
By:	/s/ Marc R. Lisker
Name:	Marc R. Lisker
Title:	Managing Director