SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person* First Reserve GP XI, Inc. (Last) (First) (Middle) ONE LAFAYETTE PLACE, THIRD FLOOR (Street) GREENWICH CT 06830 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 12/16/2009	3. Issuer Name and Ticker or Trading Symbol Cobalt International Energy, Inc. [ CIE ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) Other (specify below)	5. If Amendment, Date of Original Filed (Month/Day/Year)
			6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock	55,601,595	I	See Footnote(1)(2)(3)(5)
Common Stock	18,581,904	I	See Footnote(1)(2)(4)(5)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

1. Name and Address of Reporting Person* First Reserve GP XI, Inc. (Last) (First) (Middle) ONE LAFAYETTE PLACE, THIRD FLOOR (Street) GREENWICH CT 06830 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* First Reserve GP XI, L.P. (Last) (First) (Middle) ONE LAFAYETTE PLACE, THIRD FLOOR (Street) GREENWICH CT 06830 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* FIRST RESERVE FUND XI L P (Last) (First) (Middle) ONE LAFAYETTE PLACE, THIRD FLOOR (Street) GREENWICH CT 06830 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* FR XI Onshore AIV, L.P. (Last) (First) (Middle) ONE LAFAYETTE PLACE, THIRD FLOOR (Street) GREENWICH CT 06830 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

Explanation of Responses:

1. This Form 3 is filed on behalf of First Reserve GP XI, Inc. ("GP XI Inc."), First Reserve GP XI, L.P. ("GP XI"), First Reserve Fund XI, L.P. ("Fund XI") and FR XI Onshore AIV, L.P. ("Onshore AIV"). GP XI is the general partner of Fund XI and Onshore AIV, and GP XI Inc. is the general partner of GP XI. In such capacities, GP XI and GP XI Inc. may be deemed to have an indirect beneficial ownership in the shares of Common Stock held by Fund XI and Onshore AIV.

2. Each of Fund XI and Onshore AIV is subject to a Reorganization Agreement, dated as of December 8, 2009, pursuant to which, prior to the registered public offering of shares of Common Stock of the Issuer, Fund XI and Onshore AIV will transfer or cause to be transferred to the Issuer all of their class A interests in Cobalt International Energy, L.P., or other ownership interests in one or more persons that hold such class A interests, in exchange for the number of shares of Common Stock of the Issuer described in this Statement.

3. These shares of Common Stock are held by Fund XI.

4. These shares of Common Stock are held by Onshore AIV.

5. Pursuant to Rule 16a?1(a)(4) under the Securities Exchange Act of 1934, as amended, each of the Reporting Persons herein states that this filing shall not be deemed an admission that such Reporting Person is the beneficial owner of any of the shares of Common Stock covered by this Statement. Additionally, each Reporting Person, other than Fund XI and Onshore AIV with respect to the securities held directly by each of them, disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

Remarks:

First Reserve GP XI, Inc., by Anne E. Gold, Chief Administrative Officer, Secretary and Assistant Treasurer, is signing for itself as the designated filer, as well as in the capacity of general partner of First Reserve GP XI, L.P. First Reserve GP XI, L.P. is signing for itself and in its capacity as general partner of First Reserve Fund XI, L.P. and FR XI Onshore AIV, L.P.

	/s/ Anne E. Gold, in the capacity as described in the "Remarks" section of this Form 3	12/16/2009
	/s/ Anne E. Gold, in the capacity as described in the "Remarks" section of this Form 3	12/16/2009
	/s/ Anne E. Gold, in the capacity as described in the "Remarks" section of this Form 3	12/16/2009
	/s/ Anne E. Gold, in the capacity as described in the "Remarks" section of this Form 3	12/16/2009
	** Signature of Reporting Person	Date
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