X0304 4 2012-02-29 0 0001471261 Cobalt International Energy, Inc. CIE 0001359670 GS CAPITAL PARTNERS V GMBH & CO. KG MESSETURM FRIEDRICH-EBERT-ANLAGE 49 FRANKFURT AM MAIN 60308 2M 0000 GERMANY 0 0 1 0 0001386557 GS Capital Partners VI GmbH & Co KG 200 WEST STREET NEW YORK NY 10282 0 0 1 1 See footnotes (1), (2) and (3) 0001359609 GSCP V ADVISORS, L.L.C. 200 WEST STREET NEW YORK NY 10282 0 0 1 0 0001394286 GSCP VI Advisors, L.L.C. 200 WEST STREET NEW YORK NY 10282 0 0 1 1 See footnotes (1), (2) and (3) 0001359610 GSCP V OFFSHORE ADVISORS, L.L.C. 200 WEST STREET NEW YORK NY 10282 0 0 1 0 0001394278 GSCP VI Offshore Advisors, L.L.C. 200 WEST STREET NEW YORK NY 10282 0 0 1 1 See footnotes (1), (2) and (3) 0001359614 GS ADVISORS V, L.L.C. 200 WEST STREET NEW YORK NY 10282 0 0 1 0 0001394288 GS Advisors VI, L.L.C. 200 WEST STREET NEW YORK NY 10282 0 0 1 1 See footnotes (1), (2) and (3) 0001232073 GOLDMAN, SACHS MANAGEMENT GP GMBH 200 WEST STREET NEW YORK NY 10282 0 0 1 1 See footnotes (1), (2) and (3) Common Stock, par value $0.01 2012-02-29 4 S 0 11908050 27.16 D 62960098 I See footnotes For text of Footnote 1, see Exhibit 99.1. For text of Footnote 2, see Exhibit 99.1. For text of Footnote 3, see Exhibit 99.1. /s/ Yvette Kosic, Attorney-in-fact, GS Capital Partners V GmbH & Co. KG 2012-03-02 /s/ Yvette Kosic, Attorney-in-fact, GS Capital Partners VI GmbH & Co. KG 2012-03-02 /s/ Yvette Kosic, Attorney-in-fact, GSCP V Advisors, L.L.C. 2012-03-02 /s/ Yvette Kosic, Attorney-in-fact, GSCP VI Advisors, L.L.C. 2012-03-02 /s/ Yvette Kosic, Attorney-in-fact, GSCP V Offshore Advisors, L.L.C. 2012-03-02 /s/ Yvette Kosic, Attorney-in-fact, GSCP VI Offshore Advisors, L.L.C. 2012-03-02 /s/ Yvette Kosic, Attorney-in-fact, GS Advisors V, L.L.C. 2012-03-02 /s/ Yvette Kosic, Attorney-in-fact, GS Advisors VI, L.L.C. 2012-03-02 /s/ Yvette Kosic, Attorney-in-fact, Goldman, Sachs Management GP GmbH 2012-03-02