Cobalt International Energy, Inc. (“Cobalt”) (NYSE:CIE) today announced that it has entered into a definitive agreement with its co-owners in the Anchor development to unitize and include Cobalt’s two leases immediately south of the current Anchor unit (Green Canyon blocks 850 and 851) into the existing Anchor unit. The transfer of interests in the two leases and the revised Anchor unit are subject to customary regulatory approval. Following such approval, Cobalt will retain a 20% working interest in the revised Anchor Unit.

Timothy J. Cutt, Cobalt’s Chief Executive Officer, stated, “Expansion of the Anchor unit to include Cobalt’s two blocks to the south is key to optimizing the development plan and increasing oil recovery from Anchor as the reservoir clearly extends onto these blocks. This agreement makes Anchor even more attractive of a development going forward, whether for us or for a potential purchaser in our ongoing sales efforts.”

About Cobalt

Cobalt International Energy, Inc. (NYSE:CIE) is an independent exploration and production company active in the deepwater U.S. Gulf of Mexico and offshore 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 federal securities laws, including the safe harbor provisions of the 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,” “may,” “will,” “aim,” “estimate,” “continue,” “intend,” “could,” “expect,” “plan,” and 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 disclaims any obligation or undertaking, 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.

Cobalt International Energy, Inc.Investor Relations:Aaron Skidmore, +1 (713) 457-4426Director, Investor RelationsorMedia Relations:Lynne L. Hackedorn, +1 (713) 579-9115Vice President, Government and Public Affairs