Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
Warburg Pincus Private Equity IX, L.P.
  2. Issuer Name and Ticker or Trading Symbol
Laredo Petroleum Holdings, Inc. [LPI]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director __X__ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
C/O WARBURG PINCUS LLC, 450 LEXINGTON AVENUE
3. Date of Earliest Transaction (Month/Day/Year)
12/19/2011
(Street)

NEW YORK, NY 10017
4. If Amendment, Date Original Filed(Month/Day/Year)
6. Individual or Joint/Group Filing(Check Applicable Line)
___ Form filed by One Reporting Person
_X_ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)
4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)
6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)
7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock 12/19/2011   J(1)(2)   81,193,140 A $ 0 (1) (2) 81,193,140 D (3)  
Common Stock 12/19/2011   J(1)(2)   81,193,140 A $ 0 (1) (2) 81,193,140 I See footnotes (4) (5)

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)
5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)
6. Date Exercisable and Expiration Date
(Month/Day/Year)
7. Title and Amount of Underlying Securities
(Instr. 3 and 4)
8. Price of Derivative Security
(Instr. 5)
9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)
10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)
11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Series A-1 Preferred Units $ 0 (1) (2) 12/19/2011   J(1)(2)     58,970,000   (1)(2)   (1)(2) Common Stock 31,981,353 $ 0 (1) (2) 0 D (3)  
BOE Preferred Units $ 0 (1) (2) 12/19/2011   J(1)(2)     86,547,514   (1)(2)   (1)(2) Common Stock 49,211,787 $ 0 (1) (2) 0 D (3)  
Series A-1 Preferred Units $ 0 (1) (2) 12/19/2011   J(1)(2)     58,970,000   (1)(2)   (1)(2) Common Stock 31,981,353 $ 0 (1) (2) 0 I See footnotes (4) (5) (6)
BOE Preferred Units $ 0 (1) (2) 12/19/2011   J(1)(2)     86,547,514   (1)(2)   (1)(2) Common Stock 49,211,787 $ 0 (1) (2) 0 I See footnotes (4) (5) (6)

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
Warburg Pincus Private Equity IX, L.P.
C/O WARBURG PINCUS LLC
450 LEXINGTON AVENUE
NEW YORK, NY 10017
  X   X    
Warburg Pincus IX LLC
C/O WARBURG PINCUS LLC
450 LEXINGTON AVENUE
NEW YORK, NY 10017
  X   X    
Warburg Pincus Partners LLC
C/O WARBURG PINCUS LLC
450 LEXINGTON AVENUE
NEW YORK, NY 10017
  X   X    
WARBURG PINCUS & CO.
C/O WARBURG PINCUS LLC
450 LEXINGTON AVENUE
NEW YORK, NY 10017
  X   X    
WARBURG PINCUS LLC
C/O WARBURG PINCUS LLC
450 LEXINGTON AVENUE
NEW YORK, NY 10017
    X    
KAYE CHARLES R
C/O WARBURG PINCUS LLC
450 LEXINGTON AVENUE
NEW YORK, NY 10017
    X    
Landy Joseph P.
C/O WARBURG PINCUS LLC
450 LEXINGTON AVENUE
NEW YORK, NY 10017
    X    

Signatures

 /s/ Scott A. Arenare, Partner of Warburg Pincus & Co., as managing member of Warburg Pincus Partners LLC, as sole member of Warburg Pincus IX LLC, as general partner of Warburg Pincus Private Equity IX, L.P.   12/21/2011
**Signature of Reporting Person Date

 /s/ Scott A. Arenare, Partner of Warburg Pincus & Co., as managing member of Warburg Pincus Partners LLC, as sole member of Warburg Pincus IX LLC   12/21/2011
**Signature of Reporting Person Date

 /s/ Scott A. Arenare, Partner of Warburg Pincus & Co., as managing member of Warburg Pincus Partners LLC   12/21/2011
**Signature of Reporting Person Date

 /s/ Scott A. Arenare, Partner of Warburg Pincus & Co.   12/21/2011
**Signature of Reporting Person Date

 /s/ Scott A. Arenare, Member and Managing Director of Warburg Pincus LLC   12/21/2011
**Signature of Reporting Person Date

 /s/ Scott A. Arenare, as attorney-in-fact for Charles R. Kaye*   12/21/2011
**Signature of Reporting Person Date

 /s/ Scott A. Arenare, as attorney-in-fact for Joseph P. Landy**   12/21/2011
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) The shares of common stock, $0.01 par value per share (the "Common Stock"), of Laredo Petroleum Holdings, Inc., a Delaware corporation (the "Issuer"), were received in connection with the corporate reorganization (the "Corporate Reorganization") completed prior to the closing of the Issuer's initial public offering described in the prospectus dated December 14, 2011, in which Laredo Petroleum, LLC, a Delaware limited liability company ("Laredo LLC"), merged with the Issuer, with the Issuer being the surviving entity. In accordance with the Second Amended and Restated Limited Liability Company Agreement of Laredo LLC (the "LLC Agreement"), the Warburg Pincus Reporting Persons (as such term is defined below) received Common Stock of the Issuer in exchange for the outstanding preferred equity units of Laredo LLC listed in Table II.
(2) The number of shares of Common Stock of the Issuer that the Warburg Pincus Reporting Persons (as such term is defined below) received was based on the value that such reporting persons would have received under the distribution provisions of the LLC Agreement upon a liquidation of Laredo LLC at a liquidation value determined by reference to the initial public offering price.
(3) The stockholder is Warburg Pincus Private Equity IX, L.P., a Delaware limited partnership ("WP IX", and together with an affiliated partnership, the "WP IX Funds''). The total number of shares of Common Stock of the Issuer owned by the WP IX Funds is 81,193,140 shares of Common Stock, which includes 3,064,551 shares of Common Stock owned by WP IX Finance LP, a Delaware limited partnership that is the affiliated partnership of WP IX. WP IX Finance LP holds 2.45% of the Common Stock outstanding of the Issuer.
(4) Warburg Pincus IX LLC, a New York limited liability company ("WP IX GP''), is the general partner of WP IX. Warburg Pincus Partners LLC, a New York limited liability company ("WP Partners"), is the sole member of WP IX GP. Warburg Pincus & Co., a New York general partnership ("WP''), is the managing member of WP Partners. Warburg Pincus LLC, a New York limited liability company ("WP LLC''), manages the WP IX Funds. Charles R. Kaye and Joseph P. Landy are the Managing General Partners of WP and the Co-Presidents and Managing Members of WP LLC and may be deemed to control the WP IX Funds, WP IX GP, WP Partners, WP and WP LLC (together with Messrs. Kaye and Landy, the "Warburg Pincus Reporting Persons").
(5) By reason of the provisions of Rule 16a-1 of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), WP IX GP, WP Partners, WP, WP LLC and Messrs. Kaye and Landy may be deemed to be beneficial owners of the 81,193,140 shares of Common Stock of the Issuer held by the WP IX Funds. Pursuant to Rule 16a-1(a)(4) of the Exchange Act, each of the Warburg Pincus Reporting Persons, other than the WP IX Funds, herein states that this Form 4 shall not be deemed an admission that it or he is the beneficial owner of any of the shares of Common Stock of the Issuer reported in this Form 4. Each of the Warburg Pincus Reporting Persons disclaims beneficial ownership of the Common Stock of the Issuer, except to the extent it or he has a pecuniary interest in such shares of Common Stock.
(6) Reflects the aggregate number of preferred equity units of Laredo LLC directly owned by the WP IX Funds prior to the exchange of such units on December 19, 2011 pursuant to the Corporate Reorganization.
 
Remarks:
*Power of Attorney given by Mr. Kaye was previously filed with the U.S. Securities and Exchange Commission (the "SEC") on March 2, 2006 as an exhibit to the Schedule 13D filed by Building Products, LLC with respect to Builders FirstSource, Inc. **Power of Attorney given by Mr. Landy was previously filed with the SEC on March 2, 2006 as an exhibit to the Schedule 13D filed by Building Products, LLC with respect to Builders FirstSource, Inc. ***Information with respect to each of the Warburg Pincus Reporting Persons is given solely by such Warburg Pincus Reporting Person, and no Warburg Pincus Reporting Person has responsibility for the accuracy or completeness of information supplied by another Warburg Pincus Reporting Person. ****Solely for the purposes of Section 16 of the Exchange Act, each of the WP IX Funds, WP IX GP, WP Partners, and WP may be deemed a director-by-deputization by virtue of their contractual right to nominate a representative to serve on the board of directors of the Issuer.  Messrs. Peter R. Kagan and James R. Levy became directors of the Issuer in July 2007 and May 2007, respectively, and have been associated with WP and WP LLC since 1997 and 2006, respectively.

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