UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 ---------------------- SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No. 2)* United Therapeutics Corporation (Name of Issuer) Common Stock, $0.01 par value (Title of Class of Securities) 91307C102 (CUSIP Number) December 31, 2007 (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 purposes 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). Page 1 of 8 Pages CUSIP No. 91307C102 13G/A Page 2 of 8 Pages -------------------------------------------------------------------------------- (1) NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY) GLG Partners LP -------------------------------------------------------------------------------- (2) CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS) (a) [X] (b) [ ] -------------------------------------------------------------------------------- (3) SEC USE ONLY -------------------------------------------------------------------------------- (4) CITIZENSHIP OR PLACE OF ORGANIZATION United Kingdom -------------------------------------------------------------------------------- NUMBER OF (5) SOLE VOTING POWER 0 SHARES ----------------------------------------------------------------- BENEFICIALLY (6) SHARED VOTING POWER 0 OWNED BY ----------------------------------------------------------------- EACH (7) SOLE DISPOSITIVE POWER 0 REPORTING ----------------------------------------------------------------- PERSON WITH: (8) SHARED DISPOSITIVE POWER 0 -------------------------------------------------------------------------------- (9) AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 0 -------------------------------------------------------------------------------- (10) CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS) [ ] -------------------------------------------------------------------------------- (11) PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 0.0% -------------------------------------------------------------------------------- (12) TYPE OF REPORTING PERSON (SEE INSTRUCTIONS) PN -------------------------------------------------------------------------------- CUSIP No. 91307C102 13G/A Page 3 of 8 Pages -------------------------------------------------------------------------------- (1) NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY) GLG Partners Limited -------------------------------------------------------------------------------- (2) CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS) (a) [X] (b) [ ] -------------------------------------------------------------------------------- (3) SEC USE ONLY -------------------------------------------------------------------------------- (4) CITIZENSHIP OR PLACE OF ORGANIZATION United Kingdom -------------------------------------------------------------------------------- NUMBER OF (5) SOLE VOTING POWER 0 SHARES ----------------------------------------------------------------- BENEFICIALLY (6) SHARED VOTING POWER 0 OWNED BY ----------------------------------------------------------------- EACH (7) SOLE DISPOSITIVE POWER 0 REPORTING ----------------------------------------------------------------- PERSON WITH: (8) SHARED DISPOSITIVE POWER 0 -------------------------------------------------------------------------------- (9) AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 0 -------------------------------------------------------------------------------- (10) CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS) [ ] -------------------------------------------------------------------------------- (11) PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 0.0% -------------------------------------------------------------------------------- (12) TYPE OF REPORTING PERSON (SEE INSTRUCTIONS) IA, HC -------------------------------------------------------------------------------- CUSIP No. 91307C102 13G/A Page 4 of 8 Pages -------------------------------------------------------------------------------- (1) NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY) GLG Partners, Inc. -------------------------------------------------------------------------------- (2) CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS) (a) [X] (b) [ ] -------------------------------------------------------------------------------- (3) SEC USE ONLY -------------------------------------------------------------------------------- (4) CITIZENSHIP OR PLACE OF ORGANIZATION Delaware -------------------------------------------------------------------------------- NUMBER OF (5) SOLE VOTING POWER 0 SHARES ----------------------------------------------------------------- BENEFICIALLY (6) SHARED VOTING POWER 0 OWNED BY ----------------------------------------------------------------- EACH (7) SOLE DISPOSITIVE POWER 0 REPORTING ----------------------------------------------------------------- PERSON WITH: (8) SHARED DISPOSITIVE POWER 0 -------------------------------------------------------------------------------- (9) AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 0 -------------------------------------------------------------------------------- (10) CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS) [ ] -------------------------------------------------------------------------------- (11) PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 0.0% -------------------------------------------------------------------------------- (12) TYPE OF REPORTING PERSON (SEE INSTRUCTIONS) CO -------------------------------------------------------------------------------- CUSIP No. 91307C102 13G/A Page 5 of 8 Pages This Amendment No. 2 (this "Amendment") amends the statement on Schedule 13G filed on December 15, 2006, as amended by Amendment No. 1 filed on February 14, 2007 (as amended, the "Schedule 13G") with respect to shares of Common Stock, par value $0.01 per share (the "Shares") of United Therapeutics Corporation, a Delaware corporation (the "Company"). Capitalized terms used herein and not otherwise defined in this Amendment have the meanings set forth in the Schedule 13G. This Amendment amends and restates Items 2(a), 2(b), 2(c), 4, 5 and 10 in their entirety as set forth below. Item 2(a). Name of Person Filing This statement is filed by the entities and persons listed below, who are collectively referred to herein as "Reporting Persons," with respect to the Shares: INVESTMENT MANAGER (i) GLG Partners LP (the "Investment Manager"), with respect to the Shares held by certain funds to which the Investment Manager serves as investment manager (the "GLG Funds"). GENERAL PARTNER (ii) GLG Partners Limited (the "General Partner"), which serves as the general partner of the Investment Manager, with respect to the Shares held by each of the GLG Funds. PARENT COMPANY (iii) GLG Partners, Inc. (the "Parent Company"), which indirectly wholly owns the General Partner, with respect to the Shares held by each of the GLG Funds. The Investment Manager serves as the investment manager to each of the GLG Funds. The General Partner serves as the general partner to the Investment Manager. The Parent Company indirectly wholly owns the General Partner. On November 2, 2007, the General Partner, the Investment Manager and certain additional entities were directly or indirectly acquired by the Parent Company (formerly named Freedom Acquisition Holdings, Inc.). The Parent Company is publicly listed on the New York Stock Exchange under the ticker symbol GLG. Item 2(b). Address of Principal Business Office or, if none, Residence The address of the principal business office of the Parent Company is: 390 Park Avenue, 20th Floor New York, New York 10022 The address of the principal business office of each of the other Reporting Persons is: c/o GLG Partners LP 1 Curzon Street London W1J 5HB United Kingdom CUSIP No. 91307C102 13G/A Page 6 of 8 Pages Item 2(c). Citizenship Citizenship is set forth in Row 4 of the cover page for each Reporting Person hereto and is incorporated herein by reference for each such Reporting Person. Item 4. Ownership Provide the following information regarding the aggregate number and percentage of the class of securities of the issuer identified in Item 1. The information required by Items 4(a) - (c) is set forth in Rows 5 - 11 of the cover page for each Reporting Person hereto and is incorporated herein by reference for each such Reporting Person. Based upon the Company's Prospectus Supplement No. 7 filed on January 7, 2008, pursuant to Rule 424(b)(7) of the rules promulgated under the Securities Act of 1933, the Company had 22,239,500 Shares outstanding as of January 3, 2008. The Investment Manager, which serves as the investment manager to each of the GLG Funds, may be deemed to be the beneficial owner of all Shares owned by the GLG Funds. The Investment Manager exercises its investment authority directly or indirectly through various entities, including, without limitation, GLG Inc. The General Partner, as general partner to the Investment Manager, may be deemed to be the beneficial owner of all Shares owned by the GLG Funds. Each of Emmanuel Roman, Pierre Lagrange and Noam Gottesman are Managing Directors of the General Partner. The Parent Company, which indirectly wholly owns the General Partner, may be deemed to be the beneficial owner of all Shares owned by the GLG Funds. Each of the Investment Manager, the General Partner, the Parent Company, GLG Inc., Emmanuel Roman, Pierre Lagrange and Noam Gottesman hereby disclaims any beneficial ownership of any such Shares, except for their pecuniary interest therein. Item 5. Ownership of Five Percent 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: [X] Item 10. Certification By signing below each of the undersigned certifies that, to the best of its 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. Exhibits: Exhibit I: Joint Filing Agreement, dated as of February 14, 2008, by and among GLG Partners, Inc., GLG Partners LP and GLG Partners Limited. CUSIP No. 91307C102 13G/A Page 7 of 8 Pages SIGNATURES After reasonable inquiry and to the best of its knowledge and belief, each of the undersigned certifies that the information with respect to it set forth in this statement is true, complete, and correct. Dated: February 14, 2008 GLG PARTNERS LP Individually and in its capacity as Investment Manager GLG PARTNERS LIMITED Individually and in its capacity as General Partner of GLG Partners LP By: /s/ Timothy Kuschill --------------------------------- Timothy Kuschill Counsel of GLG Partners LP By: /s/ Victoria Parry --------------------------------- Victoria Parry, Attorney-in-Fact On behalf of Emmanuel Roman, Managing Director, GLG Partners Limited GLG PARTNERS, INC. By: /s/ Alejandro R. San Miguel --------------------------------- Name: Alejandro R. San Miguel Title: General Counsel and Corporate Secretary The Power of Attorney, dated January 14, 2008, executed by Emmanuel Roman, authorizing Victoria Parry to sign and file this Schedule 13G/A on Emmanuel Roman's behalf, which was filed with the Schedule 13G/A filed with the Securities and Exchange Commission on February 14, 2008 by such Reporting Persons with respect to the common stock of American Oil & Gas, Inc., is hereby incorporated by reference. CUSIP No. 91307C102 13G/A Page 8 of 8 Pages EXHIBIT I JOINT FILING AGREEMENT This will confirm the agreement by and among the undersigned that the Schedule 13G filed with the Securities and Exchange Commission on or about the date hereof with respect to the beneficial ownership by the undersigned of the Shares is being filed, and all amendments thereto will be filed, on behalf of each of the persons and entities named below in accordance with Rule 13d-1(k) under the Securities Exchange Act of 1934, as amended. This Agreement may be executed in two or more counterparts, each of which shall be deemed an original, but all of which together shall constitute one and the same instrument. Dated as of February 14, 2008 GLG PARTNERS LP Individually and in its capacity as Investment Manager GLG PARTNERS LIMITED Individually and in its capacity as General Partner of GLG Partners LP By: /s/ Timothy Kuschill --------------------------------- Timothy Kuschill Counsel of GLG Partners LP By: /s/ Victoria Parry --------------------------------- Victoria Parry, Attorney-in-Fact On behalf of Emmanuel Roman, Managing Director, GLG Partners Limited GLG PARTNERS, INC. By: /s/ Alejandro R. San Miguel --------------------------------- Name: Alejandro R. San Miguel Title: General Counsel and Corporate Secretary