Exhibit 99.3

Designated Filer:	Warburg Pincus Private Equity X O&G, L.P.
Issuer & Ticker Symbol:	Laredo Petroleum Holdings, Inc. [LPI]
Date of Event Requiring Statement:	September 24, 2013

Joint Filers’ Signatures

WARBURG PINCUS PRIVATE EQUITY X O&G, L.P.
By:	Warburg Pincus X, L.P., its General Partner
	By:	Warburg Pincus X LLC, its General Partner
		By:	Warburg Pincus Partners LLC, its Sole Member
			By:	Warburg Pincus & Co., its Managing Member
By:	/s/ Scott A. Arenare				Date:	September 24, 2013
	Name: Scott A. Arenare
	Title: Attorney-in-Fact*
WARBURG PINCUS X PARTNERS, L.P.
By:	Warburg Pincus X, L.P., its General Partner
	By:	Warburg Pincus X LLC, its General Partner
		By:	Warburg Pincus Partners LLC, its Sole Member
			By:	Warburg Pincus & Co., its Managing Member
By:	/s/ Scott A. Arenare				Date:	September 24, 2013
	Name: Scott A. Arenare
	Title: Attorney-in-Fact*
WARBURG PINCUS X, L.P.
By:	Warburg Pincus X LLC, its General Partner
	By:	Warburg Pincus Partners LLC, its Sole Member
		By:	Warburg Pincus & Co., its Managing Member
By:	/s/ Scott A. Arenare				Date:	September 24, 2013
	Name: Scott A. Arenare
	Title: Attorney-in-Fact*
WARBURG PINCUS X LLC
By:	Warburg Pincus Partners LLC, its Sole Member
	By:	Warburg Pincus & Co., its Managing Member
By:	/s/ Scott A. Arenare				Date:	September 24, 2013
	Name: Scott A. Arenare
	Title: Attorney-in-Fact*
WARBURG PINCUS PARTNERS LLC
By:	Warburg Pincus & Co., its Managing Member
By:	/s/ Scott A. Arenare				Date:	September 24, 2013
	Name: Scott A. Arenare
	Title: Attorney-in-Fact*

WARBURG PINCUS LLC
By:	/s/ Scott A. Arenare	Date:	September 24, 2013
	Name: Scott A. Arenare
	Title: Managing Director
WARBURG PINCUS & CO.
By:	/s/ Scott A. Arenare	Date:	September 24, 2013
	Name: Scott A. Arenare
	Title: Attorney-in-Fact*
CHARLES R. KAYE
By:	/s/ Scott A. Arenare	Date:	September 24, 2013
	Name: Charles R. Kaye
	By: Scott A. Arenare, Attorney-in-Fact*
JOSEPH P. LANDY
By:	/s/ Scott A. Arenare	Date:	September 24, 2013
	Name: Joseph P. Landy
	By: Scott A. Arenare, Attorney-in-Fact*

* The Power of Attorney given by each of Warburg Pincus & Co., Mr. Kaye and Mr. Landy was previously filed with the U.S. Securities & Exchange Commission on January 15, 2013 as an exhibit to a statement on Schedule 13D/A filed by Warburg Pincus Private Equity X, L.P. with respect to Talon Therapeutics, Inc. and is hereby incorporated by reference.