Cobalt International Energy, Inc. (“Cobalt”) (NYSE:CIE) today announced that it has commenced a registered underwritten public offering of 40,000,000 shares of its common stock, all of which will be offered by selling stockholders. The underwriters of this offering have been granted an option, exercisable within 30 days, to purchase up to an additional 6,000,000 shares of common stock from certain of the selling stockholders on the same terms and conditions. Cobalt will not receive any of the proceeds from the sale of the shares of common stock. Morgan Stanley & Co. LLC and Citigroup are acting as the underwriters of the offering. The offering is being made pursuant to an effective shelf registration statement, including a prospectus and a preliminary prospectus supplement relating to the offering, filed by Cobalt with the Securities and Exchange Commission (“SEC”). When available, copies of the prospectus and the preliminary prospectus supplement relating to the offering may be obtained for free by visiting the SEC website at www.sec.gov. Alternatively, copies of the prospectus and the preliminary prospectus supplement may be obtained from Morgan Stanley & Co. LLC, Attn: Prospectus Department, 180 Varick Street, 2nd Floor, New York, New York 10014, by calling (866) 718-1649 or (917) 606-8474 or by emailing firstname.lastname@example.org and from Citigroup, c/o Broadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, NY 11717, or by calling (800) 831-9146. This press release is for informational purposes only and does not constitute an offer to sell, or a solicitation of an offer to buy, nor shall there be any sale of these securities in any state or jurisdiction in which such an offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or jurisdiction. Any offer or sale of these securities will be made only by means of a prospectus, including a prospectus supplement, forming a part of the related registration statement.