JOINT FILING AGREEMENTJoint Filing Agreement • December 22nd, 2011 • Warburg Pincus Private Equity IX, L.P. • Crude petroleum & natural gas
The undersigned each agree that (i) the statement on Schedule 13G relating to the common stock of Laredo Petroleum Holdings, Inc., a Delaware corporation, has been adopted and filed on behalf of each of them, (ii) all future amendments to such statement on Schedule 13G will, unless written notice to the contrary is delivered as described below, be jointly filed on behalf of each of them, and (iii) the provisions of Rule 13d-1(k)(1) under the Securities Exchange Act of 1934 apply to each of them. This agreement may be terminated with respect to the obligation to jointly file future amendments to such statement on Schedule 13G as to any of the undersigned upon such person giving written notice thereof to each of the other persons signatory hereto, at the principal office thereof. In evidence thereof, the undersigned, being duly authorized, have executed this Joint Filing Agreement as of December 22, 2011.
