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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1. Name and Address of Reporting Person * INFRASTRUX HOLDINGS, LLC   2. Issuer Name and Ticker or Trading Symbol Willbros Group, Inc.\NEW\ [WG] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director __X__ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O TENASKA CAPITAL MANAGEMENT, LLC, 1044 N 115TH STREET, SUITE 400 3. Date of Earliest Transaction (Month/Day/Year) 05/24/2011 (Street) OMAHA, NE 68154-4446 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 05/24/2011   A   16,742 A $ 0 7,936,318 D (1)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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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

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
INFRASTRUX HOLDINGS, LLC C/O TENASKA CAPITAL MANAGEMENT, LLC 1044 N 115TH STREET, SUITE 400 OMAHA, NE 68154-4446		X
TPF POWER, INC. C/O TENASKA CAPITAL MANAGEMENT, LLC 1044 N 115TH STREET, SUITE 400 OMAHA, NE 68154-4446		X
TPF INFRASTRUX HOLDINGS, LLC C/O TENASKA CAPITAL MANAGEMENT, LLC 1044 N 115TH STREET, SUITE 400 OMAHA, NE 68154-4446		X
TENASKA POWER FUND, LP C/O TENASKA CAPITAL MANAGEMENT, LLC 1044 N 115TH STREET, SUITE 400 OMAHA, NE 68154-4446		X
TENASKA PF G, LLC C/O TENASKA CAPITAL MANAGEMENT, LLC 1044 N 115TH STREET, SUITE 400 OMAHA, NE 68154-4446		X
TENASKA PF, INC. C/O TENASKA CAPITAL MANAGEMENT, LLC 1044 N 115TH STREET, SUITE 400 OMAHA, NE 68254-4446		X

Signatures

Ryan T. Schroer, Vice President of TPF Power, Inc., Manager of INFRASTRUX HOLDINGS, LLC		09/19/2011
**Signature of Reporting Person		Date
Ryan T. Schroer, Vice President of TPF POWER, INC.		09/19/2011
**Signature of Reporting Person		Date
Ryan T. Schroer, Vice President of TPF Power, Inc., Manager of TPF INFRASTRUX HOLDINGS, LLC		09/19/2011
**Signature of Reporting Person		Date
Ryan T. Schroer, Vice President of Tenaska PF, Inc., Manager of Tenaska PF G, LLC, General Partner of TENASKA POWER FUND, L.P.		09/19/2011
**Signature of Reporting Person		Date
Ryan T. Schroer, Vice President of Tenaska PF, Inc., Manager of TENASKA PF G, LLC		09/19/2011
**Signature of Reporting Person		Date
Ryan T. Schroer, Vice President of TENASKA PF, INC.		09/19/2011
**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)	These shares are indirectly owned by TPF Power, Inc., the manager of InfrastruX Holdings, LLC, TPF InfrastruX Holdings, LLC, the majority owner of InfrastruX Holdings, LLC, Tenaska Power Fund, L.P., the sole owner of TPF InfrastruX Holdings, LLC, Tenaska PF G, LLC, the general partner of Tenaska Power Fund, L.P., and Tenaska PF, Inc., the manager of Tenaska PF G, LLC. These entities may be deemed indirect beneficial owners of the reported securities.

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