Cobalt International Energy, Inc. (“Cobalt”) (NYSE:CIE) today announced the closing of the previously announced registered underwritten public offering of shares of its common stock, all of which were sold by funds affiliated with First Reserve Corporation, Goldman, Sachs & Co., Riverstone Holdings LLC and The Carlyle Group, and KERN Partners Ltd. and certain limited partners in such funds affiliated with KERN Partners Ltd. (collectively, the “selling stockholders”). The selling stockholders sold a total of 40,000,000 shares of Cobalt’s common stock. The underwriters also may purchase up to an additional 6,000,000 shares of common stock from certain of the selling stockholders should the underwriters exercise their over-allotment option. Cobalt will not receive any of the proceeds from the sale of the shares of common stock. Morgan Stanley & Co. LLC and Citigroup acted as the underwriters of the offering. Cobalt today also announced that, as a result of the secondary offering and the selling stockholders now owning in the aggregate less than 50% of Cobalt’s total outstanding shares of common stock, Cobalt is no longer a “controlled company” for purposes of certain exemptions from the NYSE corporate governance standards. Accordingly, Cobalt will be required to comply with, among other things, the NYSE’s board and committee independence requirements within the time periods required by the NYSE rules. In addition, certain provisions set forth in Cobalt’s certificate of incorporation and bylaws take effect regarding, among other things, the election and removal of directors from Cobalt’s board and the ability of stockholders to take action by written consent or call special meetings of stockholders. About Cobalt Cobalt is an independent oil exploration and production company focusing on the deepwater U.S. Gulf of Mexico and offshore Angola and Gabon in West Africa. Cobalt was formed in 2005 and is headquartered in Houston, Texas. Forward-Looking Statements This press release 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 Cobalt’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 Cobalt’s SEC filings. Cobalt 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. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of this press release. All forward-looking statements are qualified in their entirety by this cautionary statement.