Cobalt International Energy, Inc. (“Cobalt”) (NYSE:CIE) today announced that it has commenced a registered underwritten public offering of $1,200,000,000 aggregate principal amount of its convertible senior notes due 2019 (the “Notes”). The underwriters of this offering have been granted an option, exercisable within 13 days, to purchase up to an additional $180,000,000 aggregate principal amount of the Notes from Cobalt on the same terms and conditions to cover over-allotments, if any. The Notes will be Cobalt’s senior unsecured obligations and interest will be payable semi-annually in arrears on June 1 and December 1 of each year, beginning on June 1, 2013. The Notes will mature on December 1, 2019, unless earlier repurchased or converted in accordance with their terms. The Notes will be convertible at the holder’s option at any time prior to 5:00 p.m., New York City time, on the second scheduled trading day immediately preceding the maturity date into cash, shares of Cobalt’s common stock or a combination of cash and shares of Cobalt’s common stock, at Cobalt’s election. The interest rate, conversion rate, conversion price and other terms of the notes will be determined by Cobalt and the underwriters. Cobalt intends to use the net proceeds from the sale of the Notes to fund its capital expenditures and for general corporate purposes. Morgan Stanley & Co. LLC and Goldman, Sachs & Co. 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 by emailing firstname.lastname@example.org and from Goldman, Sachs & Co., Attn: Prospectus Department, 200 West Street, New York, NY 10282, by calling 1-866-471-2526 or by emailing email@example.com. 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.