UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT
Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of Earliest Event Reported): May 7, 2013

Cobalt International Energy, Inc.

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (713) 579-9100

N/A

(Former name or former address if changed since last report.)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

o Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

o Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

o Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

o Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Item 1.01                         Entry into a Material Definitive Agreement.

On May 7, 2013, Cobalt International Energy, Inc. (the “Company”), in connection with a registered underwritten secondary public offering of shares of its common stock (the “Offering”), entered into an underwriting agreement (the “Underwriting Agreement”) with Citigroup Global Markets Inc., as underwriter (the “Underwriter”) of the Offering, and the selling stockholders named in Schedule A thereto (the “Selling Stockholders”), pursuant to which the Selling Stockholders agreed to sell to the Underwriter 50,000,000 shares of the Company’s common stock.  In addition, pursuant to the Underwriting Agreement, the Underwriter has been granted an option, exerisable within 30 days, to purchase up to an additional 7,500,000 shares of common stock on the same terms and conditions to cover over-allotments, if any. The Company will not receive any proceeds from the sale of the shares of common stock in the Offering.

A copy of the Underwriting Agreement is contained in Exhibit 1.1 hereto, which exhibit is incorporated by reference into this Item 1.01. The above description is qualified in its entirety by reference to such exhibit.

A copy of the Underwriting Agreement has been included to provide security holders with information regarding its terms. It is not intended to provide any other factual information about the Company or the Selling Stockholders. The representations, warranties and covenants contained in the Underwriting Agreement were made solely for purposes of the Offering and as of specific dates, were solely for the benefit of the parties to the Underwriting Agreement, may be subject to limitations agreed upon by the contracting parties, including being qualified by confidential disclosures made for the purposes of allocating contractual risk between the parties to the Underwriting Agreement instead of establishing these matters as facts, and may be subject to standards of materiality applicable to the contracting parties that differ from those applicable to security holders. Security holders are not third-party beneficiaries under the Underwriting Agreement and should not rely on the representations, warranties and covenants or any descriptions thereof as characterizations of the actual state of facts or condition of the Company. Moreover, information concerning the subject matter of the representations and warranties may change after the date of the Underwriting Agreement, which subsequent information may or may not be fully reflected in the Company’s public disclosures.

In connection with the Offering, the following exhibits are filed with this Current Report on Form 8-K and are incorporated by reference into the Company’s Registration Statement on Form S-3 (Registration No. 333-171536) relating to the Offering: (i) the Underwriting Agreement (Exhibit 1.1 to this Current Report on Form 8-K), and (ii) the legal opinion of Davis Polk & Wardwell LLP (including the consent of Davis Polk & Wardwell LLP) (Exhibit 5.1 to this Current Report on Form 8-K).

Forward-Looking Statements

This Current Report on Form 8-K includes “forward-looking statements” within the meaning of the safe harbor provisions of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934 — that is, statements related to future, not past, events. Forward-looking statements are based on current expectations and include any statement that does not directly relate to a current or historical fact. In this context, forward-looking statements often address the Company’s expected future business and financial performance, and often contain words such as “anticipate,” “believe,” “intend,” “expect,” “plan,” “will” or other similar words. These forward-looking statements involve certain risks and uncertainties that ultimately may not prove to be accurate. Actual results and future events could differ materially from those anticipated in such statements. For further discussion of risks and uncertainties, individuals should refer to the Company’s SEC filings. The Company undertakes no obligation and does not intend to update these forward-looking statements to reflect events or circumstances occurring after this press release, other than as required by law. Investors are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of this Current Report on Form 8-K. All forward-looking statements are qualified in their entirety by this cautionary statement.

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Item 9.01.                            Financial Statements and Exhibits.

(d) Exhibits

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SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Date: May 10, 2013

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EXHIBIT LISTING

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