Summary of KOSMOS ENERGY LTD.

Entry into a Material Definitive Agreement, Regulation FD Disclosure, Financia

Item 1.01 Entry into a Material Definitive Agreement.

On February 8, 2013, Kosmos Energy Ltd. (the "Company") entered into Amendment No. 1 (the "Amendment") to the Amended and Restated Registration Rights Agreement dated as of October 7, 2009 (the "RRA"), with certain funds affiliated with Warburg Pincus LLC (the "Warburg Pincus Funds") and The Blackstone Group L.P. (the "Blackstone Funds"), respectively, as existing shareholders of the Company's common shares, par value $0.01 per share (the "common shares"). The Amendment, among other things, shortens the notice period required to be given by the Company to holders of Registrable Securities (as defined in the RRA) upon either the Warburg Pincus Funds or the Blackstone Funds making a demand for registration of their Registrable Securities under the Securities Act of 1933, as amended (the "Securities Act"), or the Company proposing to effect a registration of its common shares under the Securities Act, to one day.

Based on share ownership as of December 31, 2012, after giving effect to the Offering (as defined in Item 7.01 below) and assuming no exercise of the underwriters' over-allotment option in connection with the Offering, the Warburg Pincus Funds will own approximately 35.84% of the Company's outstanding common shares, and the Blackstone Funds will own approximately 29.32% of the Company's outstanding common shares. In addition, two of the Company's directors, Joseph P. Landy and David B. Krieger, are affiliated with the Warburg Pincus Funds, and two of the Company's directors, David I. Foley and Prakash A. Melwani, are affiliated with the Blackstone Funds. These directors were designated to the Company's board of directors pursuant to the terms of a shareholders agreement among the Company, the Warburg Pincus Funds and the Blackstone Funds dated as of May 10, 2011.

Item 7.01 Regulation FD.

On February 14, 2013, the Company announced the pricing of the previously announced registered underwritten public offering of common shares (the "Offering"). The Warburg Pincus Funds, the Blackstone Funds and certain officers of the Company participating in the Offering (collectively, the "Selling Shareholders") have agreed to sell an aggregate of 30,000,000 common shares at a public offering price of $11.00 per common share. The Offering is expected to close on February 21, 2013, subject to customary closing conditions. A press release announcing the pricing of the Offering is contained in Exhibit 99.1 hereto, which exhibit is incorporated by reference into this Item 7.01.

The information contained herein is being furnished, not filed, pursuant to Item
7.01. Accordingly, this information will not be incorporated by reference into any registration statement filed by the Company under the Securities Act of 1933, as amended, unless specifically identified therein as being incorporated therein by reference.