Exhibit 10.1

Execution Version

FIRST AMENDMENT

TO

FOURTH AMENDED AND RESTATED

SENIOR REVOLVING CREDIT AGREEMENT

among

PETROHAWK ENERGY CORPORATION,

as the Borrower,

BNP PARIBAS,

as Administrative Agent,

BANK OF AMERICA, N.A. and

BANK OF MONTREAL,

as Co-Syndication Agents,

JPMORGAN CHASE BANK, N.A. and

WELLS FARGO BANK, N.A.,

as Co-Documentation Agents,

and

THE LENDERS PARTY HERETO

Dated as of May 17, 2010

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FIRST AMENDMENT TO

FOURTH AMENDED AND RESTATED SENIOR REVOLVING CREDIT AGREEMENT

This FIRST AMENDMENT TO FOURTH AMENDED AND RESTATED SENIOR REVOLVING CREDIT
AGREEMENT (this “First Amendment”) executed as of May 17, 2010 is among
PETROHAWK ENERGY CORPORATION, a corporation duly formed and existing under the
laws of the State of Delaware (the “Borrower”); each of the Guarantors signatory
hereto (the “Guarantors”); each of the Lenders from time to time party hereto;
BNP PARIBAS (in its individual capacity, “BNP Paribas”), as administrative agent
for the Lenders (in such capacity, together with its successors in such
capacity, the “Administrative Agent”); BANK OF AMERICA, N.A. and BANK OF
MONTREAL, as co-syndication agents for the Lenders (in such capacity, together
with their successors in such capacity, the “Co-Syndication Agents”); and
JPMorgan Chase Bank, N.A. and Wells Fargo Bank, as co-documentation agents for
the Lenders (in such capacity, together with their successors in such capacity,
the “Co-Documentation Agents”).

Recitals

A. The Borrower, the Administrative Agent, the other Agents and Lenders named
and defined therein as lenders and agents, are parties to that certain Fourth
Amended and Restated Senior Revolving Credit Agreement dated as of October 14,
2009, pursuant to which such lenders and agents provided certain loans and
extensions of credit to the Borrower (as amended, the “Credit Agreement”).

B. The Borrower has requested, and the Borrower, the Administrative Agent, the
Co-Syndication Agents, the Co-Documentation Agents and Lenders have agreed to
amend certain provisions of the Credit Agreement.

C. NOW, THEREFORE, in consideration of the premises and the mutual covenants
herein contained, for good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the parties hereto agree as
follows:

Section 1. Defined Terms. Each capitalized term which is defined in the Credit
Agreement, but which is not defined in this First Amendment, shall have the
meaning ascribed such term in the Credit Agreement. Unless otherwise indicated,
all section references in this First Amendment refer to sections in the Credit
Agreement.

Section 2. Amendments to Credit Agreement.

2.1 Certain Defined Terms. The following defined terms in Section 1.02 are
hereby amended and restated, or added, in their entirety as follows:

“‘Agreement’ means this Fourth Amended and Restated Senior Revolving Credit
Agreement, as amended by the First Amendment to Fourth Amended and Restated
Senior Revolving Credit Agreement, dated as of May 17, 2010, as the same may
from time to time be further amended, modified, supplemented or restated.

 

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‘EBITDA-HFS’ means, for any period, the sum of Consolidated Net Income-HFS for
such period plus (a) the following expenses or charges to the extent deducted
from Consolidated Net Income in such period: interest, income taxes,
depreciation, depletion, amortization and all other non-cash charges and
(b) minus all non-cash income to the extent included in Consolidated Net
Income-HFS and minority interest income of Newco.

‘Formation and Contribution Agreement’ means that certain Formation and
Contribution Agreement by and among the Borrower, Hawk Field Services and KM
Gathering LLC made and entered into as of April 12, 2010.

‘Gathering Contract’ means that certain Firm Gas Gathering Agreement effective
January 1, 2009 between Petrohawk Operating Company (Shipper) and Hawk Field
Services (Gatherer).

‘Newco’ means KinderHawk Field Services LLC, a Delaware limited liability
company, and a joint venture company owned directly or indirectly by Hawk Field
Services (50%) and Kinder Morgan Energy Partners, L.P. (50%).

‘Newco LLC Agreement’ means the limited liability company agreement of Newco to
be entered into pursuant to the Formation and Contribution Agreement.

‘Unrestricted Subsidiary’ means any Subsidiary of the Borrower designated as
such on Schedule 7.14 or which the Borrower has designated in writing to the
Administrative Agent to be an Unrestricted Subsidiary pursuant to Section 9.06
and, in the event Newco becomes a Subsidiary of Hawk Field Services and/or the
Borrower, Newco.”

2.2 Amendment to Section 7.13. Section 7.13 is hereby amended and restated as
follows:

“Section 7.13. Restriction on Liens. Neither the Borrower nor any of the
Restricted Subsidiaries is a party to any material agreement or arrangement
(other than Capital Leases creating Liens permitted by Section 9.03(c), but then
only on the Property subject of such Capital Lease, and pursuant to the Newco
LLC Agreement with respect to Hawk Field Services’s Equity Interest in Newco),
or subject to any order, judgment, writ or decree, which either restricts or
purports to restrict its ability to grant Liens to the Administrative Agent and
the Lenders on or in respect of their Properties to secure the Indebtedness and
the Loan Documents.”

2.3 Amendment to Section 8.19(b). Section 8.19(b) is hereby amended and restated
as follows:

“(b) The Borrower shall cause Hawk Field Services and each of its Restricted
Subsidiaries to perform and observe in all material respects all the terms and
provisions of each Midstream Services contract of Hawk Field Services and its
Restricted Subsidiaries to be performed or observed by them, maintain each such

 

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Midstream Services contract in full force and effect, and enforce each such
Midstream Services contract in accordance with its terms, provided that Hawk
Field Services may terminate the Gathering Contract and assign, transfer and
convey the Haynesville Applicable Contracts (as such term is defined in the
Formation and Contribution Agreement) to Newco contemporaneous with the
execution of the Newco LLC Agreement.

2.4 Amendment to Section 9.05. Section 9.05 is hereby amended by adding the
following subsection (m):

“(m) Investments in Newco (i) in the form of the contribution of the Haynesville
Assets (as such term is defined in the Formation and Contribution Agreement) and
(ii) in an additional amount of up to $201,300,000 from and after the date of
the contribution referred to in clause (i) of this subsection (m).”

2.5 Amendment to Section 9.06(b). Section 9.06(b) is hereby amended by adding
the following at the end thereof:

“Notwithstanding anything herein to the contrary, in the event Newco becomes a
Subsidiary of Hawk Field Services and/or the Borrower, Newco shall be an
Unrestricted Subsidiary.”

2.6 Amendment to Section 9.13. Section 9.13 is hereby amended by changing the
word “Company” to “Borrower” in Section 9.13(g), by renumbering Section 9.13(h)
as Section 9.13(i) and inserting the following as Section 9.13(h) immediately
before the “and” at the end of subsection (g):

“(h) contribution of the Haynesville Assets (as such term is defined in the
Formation and Contribution Agreement) to Newco contemporaneous with the
execution of the Newco LLC Agreement;”

2.7 Amendment to Section 9.16. Section 9.16 is hereby amended and restated as
follows:

“Section 9.16 Subsidiaries. The Borrower will not, and will not permit any
Restricted Subsidiary to, create or acquire any additional Restricted Subsidiary
or redesignate an Unrestricted Subsidiary as a Restricted Subsidiary unless the
Borrower gives written notice to the Administrative Agent of such creation or
acquisition and complies with Section 8.14 (b) and Section 8.14(c). The Borrower
shall not, and shall not permit any Restricted Subsidiary to, sell, assign or
otherwise dispose of any Equity Interests in any Restricted Subsidiary except in
compliance with Section 9.13(e), (f) or (g).”

2.8 Amendment to Section 9.17. Section 9.17 is hereby amended by renumbering
Section 9.17(e) as Section 9.17(f) and inserting the following as
Section 9.17(e) immediately before the “or” at the end of clause (d):

“(e) any restriction with respect to Hawk Field Services’s Equity Interest in
Newco imposed by the Newco LLC Agreement,”

 

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2.9 Amendment to Section 9.20. Section 9.20 is hereby amended by adding the
following at the end thereof:

“Notwithstanding the foregoing, Hawk Field Services may terminate the Gathering
Contract and assign, transfer and convey the Haynesville Applicable Contracts
(as such term is defined in the Formation and Contribution Agreement) to Newco
contemporaneous with the execution of the Newco LLC Agreement.”

Section 3. Adjustment to Midstream Component. Upon the execution of the Newco
LLC Agreement until the next Midstream Component Determination Date, the
Midstream Component shall be $49,963,000. Notwithstanding the foregoing, the
Midstream Component may be subject to further adjustment pursuant to
Section 9.13.

Section 4. Assignments, New Lenders and Reallocation of Commitments and Loans.
Each Lender party to the Credit Agreement immediately prior to the First
Amendment Effective Date (as defined below) and designated as an Adjusting
Lender on Annex I (the “Adjusting Lenders”) has, in consultation with the
Borrower, agreed to reallocate its respective Maximum Credit Amount and
Commitment and to, among other things, allow Deutsche Bank Trust Company
Americas to become a party to the Credit Agreement as a Lender, (the “New
Lender”) by acquiring an interest in the total Maximum Credit Amounts and
Commitments. The Administrative Agent and the Borrower hereby consent to such
reallocation and the New Lender’s acquisition of an interest in the Maximum
Credit Amounts and Commitments and the Adjusting Lenders’ assignments of their
Commitments. On the First Amendment Effective Date and after giving effect to
such reallocations, the Maximum Credit Amounts and Commitment of each Lender
(including both the Adjusting Lenders and the New Lender) shall be as set forth
on Annex I of this First Amendment which Annex I supersedes and replaces the
Annex I to the Credit Agreement. With respect to such reallocation, the New
Lender shall be deemed to have acquired the Maximum Credit Amount and Commitment
allocated to it from each of the Adjusting Lenders pursuant to the terms of the
Assignment and Assumption Agreement attached as Exhibit G to the Credit
Agreement (the “Assignment Agreement”). On the First Amendment Effective Date,
the New Lender and each Adjusting Lender shall be deemed to have entered into
separate Assignment Agreements pursuant to each of which (i) the New Lender
shall be the “Assignee”, (ii) each Adjusting Lender shall be the “Assignor”,
(iii) the term “Effective Date” shall be the “First Amendment Effective Date” as
defined herein and (iv) item 6 therein shall be deemed to be deleted.
Notwithstanding Section 12.04(b)(ii)(C), the Lenders deemed to be parties to
such Assignment Agreements shall not be required to pay a processing and
recordation fee of $3,500 to the Administrative Agent. On the First Amendment
Effective Date, the Administrative Agent shall take the actions specified in
Section 12.04(b)(v), including recording the assignments described herein in the
Register, and such assignments shall be effective for purposes of the Credit
Agreement.

The Lenders and the Borrower acknowledge and stipulate that Section 4.06 of the
Credit Agreement describes events that were consummated on the Effective Date of
the Credit Agreement. The parties further stipulate that the reference to Annex
I in Section 4.06 of the Credit Agreement is a reference to “Annex I, as
amended, restated, supplemented, replaced or otherwise modified pursuant to this
Agreement.”

 

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Section 5. Conditions Precedent. The effectiveness of this First Amendment is
subject to the receipt by the Administrative Agent of the following documents
and satisfaction of the other conditions provided in this Section 5, each of
which shall be reasonably satisfactory to the Administrative Agent in form and
substance (the date on which such documents are received and conditions
satisfied or waived pursuant to the Credit Agreement, the “First Amendment
Effective Date”):

5.1 The Administrative Agent and the Lenders shall have received all fees and
other amounts due and payable on or prior to the First Amendment Effective Date,
including, to the extent invoiced, reimbursement or payment of all out-of-pocket
expenses required to be reimbursed or paid by the Borrower hereunder.

5.2 The Administrative Agent shall have received from the Borrower, the Majority
Lenders, including each Adjusting Lender, and each of the Guarantors,
counterparts (in such number as may be requested by the Administrative Agent) of
this First Amendment signed on behalf of such Person.

5.3 The Administrative Agent shall have received a certificate of a Responsible
Officer of the Borrower certifying: (a) that the Borrower has or is concurrently
consummating the formation of Newco and the assignment, transfer and conveyance
to Newco of the Haynesville Assets in accordance with the terms of the Formation
and Contribution Agreement (with all of the material conditions precedent
thereto having been satisfied in all material respects by the parties thereto);
(b) as to the amount of the Closing Cash Contribution (as such term is defined
in the Formation and Contribution Agreement); and (c) such other related
documents and information as the Administrative Agent shall have reasonably
requested.

5.4 No Default or Event of Default shall have occurred and be continuing as of
the First Amendment Effective Date.

5.5 The Administrative Agent shall have received such other documents as the
Administrative Agent or its special counsel may reasonably require.

The Administrative Agent is hereby authorized and directed to declare this First
Amendment to be effective when it has received documents confirming or
certifying, to the satisfaction of the Administrative Agent, compliance with the
conditions set forth in this Section 5 or the waiver of such conditions as
permitted hereby. Such declaration shall be final, conclusive and binding upon
all parties to the Credit Agreement for all purposes.

Section 6. Representations and Warranties; Etc. The Borrower and each Guarantor
hereby affirms: (a) that as of the date of execution and delivery of this First
Amendment, and after giving effect to the transactions contemplated hereby, all
of the representations and warranties contained in each Loan Document to which
it is a party are true and correct in all material respects (unless made as of a
specific earlier date, in which case, was true as of such date); and (b) that
after giving effect to this First Amendment, no Defaults exist under the Loan
Documents or will exist under the Loan Documents.

 

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Section 7. Miscellaneous.

7.1 Confirmation. The provisions of the Credit Agreement (as amended by this
First Amendment) shall remain in full force and effect in accordance with its
terms following the effectiveness of this First Amendment.

7.2 Ratification and Affirmation of Borrower and Guarantors. The Borrower and
Guarantors hereby expressly (a) acknowledge the terms of this First Amendment,
(b) ratify and affirm their obligations under the Loan Documents to which they
are a party, (c) acknowledge, renew and extend their continued liabilities under
the Guarantee Agreement and the other Security Instruments to which they are a
party and agree that their guarantee under the Guarantee Agreement and the other
Security Instruments to which they are a party remains in full force and effect
with respect to the Indebtedness as amended hereby.

7.3 Counterparts. This First Amendment may be executed by one or more of the
parties hereto in any number of separate counterparts, and all of such
counterparts taken together shall be deemed to constitute one and the same
instrument.

7.4 No Oral Agreement. THIS WRITTEN FIRST AMENDMENT, THE CREDIT AGREEMENT AND
THE OTHER LOAN DOCUMENTS EXECUTED IN CONNECTION HEREWITH AND THEREWITH REPRESENT
THE FINAL AGREEMENT BETWEEN THE PARTIES AND MAY NOT BE CONTRADICTED BY EVIDENCE
OF PRIOR, CONTEMPORANEOUS, OR UNWRITTEN ORAL AGREEMENTS OF THE PARTIES. THERE
ARE NO SUBSEQUENT ORAL AGREEMENTS BETWEEN THE PARTIES.

7.5 Governing Law. THIS FIRST AMENDMENT (INCLUDING, BUT NOT LIMITED TO, THE
VALIDITY AND ENFORCEABILITY HEREOF) SHALL BE GOVERNED BY, AND CONSTRUED IN
ACCORDANCE WITH, THE LAWS OF THE STATE OF TEXAS.

7.6 Release of Lien. The Majority Lenders hereby authorize the Administrative
Agent, pursuant to Section 9.13 and Section 11.10 of the Credit Agreement and
contemporaneous with the execution of the Newco LLC Agreement, to release,
execute and deliver to the Borrower, at the Borrower’s sole cost and expense,
any and all releases of Liens, termination statements, assignments or other
documents reasonably requested by the Borrower in connection with the
contribution of the Haynesville Assets to Newco. Pursuant to the foregoing
authorization, the Administrative Agent hereby releases any Liens granted to it
on the Haynesville Assets.

 

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IN WITNESS WHEREOF, the parties hereto have caused this First Amendment to be
duly executed effective as of the date first written above.

 

BORROWER:     PETROHAWK ENERGY CORPORATION     By:   /s/ David S. Elkouri      
Name:   David S. Elkouri       Title:  

Executive Vice President-

General Counsel and Secretary

First Amendment – Fourth Amended and Restated Senior Revolving Credit Agreement

Signature Page

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GUARANTORS:     PETROHAWK OPERATING COMPANY     P-H ENERGY, LLC     HAWK FIELD
SERVICES, LLC     PETROHAWK PROPERTIES, LP       By:  

P-H Energy, L.L.C.

Its General Partner

      WINWELL RESOURCES, L.L.C.       WSF, INC.       KSC RESOURCES, INC.      
KCS ENERGY SERVICES, LLC       MEDALLION CALIFORNIA PROPERTIES COMPANY      
PROLIQ, INC.       ONE TEC, LLC       ONE TEC OPERATING, LLC       BISON RANCH
LLC       PETROHAWK HOLDINGS, LLC       HK TRANSPORTATION, LLC       By:   /s/
David S. Elkouri       Name:   David S. Elkouri       Title:  

Executive Vice President-

General Counsel and Secretary

      HK ENERGY MARKETING, LLC       By:   /s/ Steve W. Herod       Name:  
Steve W. Herod       Title:   President

First Amendment – Fourth Amended and Restated Senior Revolving Credit Agreement

Signature Page

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ADMINISTRATIVE AGENT:    

BNP PARIBAS,

as Administrative Agent and Lender

    By:   /s/ Juan Carlos Sandoval       Name:   Juan Carlos Sandoval      
Title:   Vice President       By:   /s/ Edward Pak       Name:   Edward Pak    
  Title:   Vice President CO-SYNDICATION AGENTS:     BANK OF AMERICA, N.A., as
Co-Syndication Agent and Lender       By:   /s/ Jeffrey H. Ratbkamp       Name:
  Jeffrey H. Ratbkamp       Title:   Managing Director       BANK OF MONTREAL,
as Co-Syndication Agent and Lender       By:   /s/ James V. Ducote       Name:  
James V. Ducote       Title:   Director CO-DOCUMENTATION AGENTS:     JPMORGAN
CHASE BANK, N.A., as Co-Documentation Agent and Lender       By:   /s/ Michael
A. Kamauf       Name:   Michael A. Kamauf       Title:   Vice President      
WELLS FARGO BANK, N.A., as Co-Documentation Agent and Lender       By:   /s/
Doug McDowell       Name:   Doug McDowell       Title:  

Vice President

Senior Portfolio Manager

First Amendment – Fourth Amended and Restated Senior Revolving Credit Agreement

Signature Page

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LENDERS:     ROYAL BANK OF CANADA     By:   /s/ Jay T. Sartain       Name:   Jay
T. Sartain       Title:   Authorized Signatory       BARCLAYS BANK PLC     By:  
/s/ Sam Yoo       Name:   Sam Yoo       Title:   Assistant Vice President      
MORGAN STANLEY BANK, N.A.     By:   /s/ Ryan Vetsch       Name:   Ryan Vetsch  
    Title:   Authorized Signatory       CREDIT AGRICOLE CORPORATE AND INVESTMENT
BANK     By:   /s/ Sharada Manne       Name:   Sharada Manne       Title:  
Director       By:   /s/ Dixon Schultz       Name:   Dixon Schultz       Title:
  Director       CREDIT SUISSE, CAYMAN ISLANDS BRANCH     By:   /s/ Mikhail
Faybusovich       Name:   Mikhail Faybusovich       Title:   Vice President    
By:   /s/ Vipul Dhadda       Name:   Vipul Dhadda       Title:   Associate

First Amendment – Fourth Amended and Restated Senior Revolving Credit Agreement

Signature Page

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LENDERS:     DEUTSCHE BANK TRUST COMPANY AMERICAS     By:   /s/ Marcus M.
Tarkington       Name:   Marcus M. Tarkington       Title:   Director     By:  
/s/ Omayra Laucella       Name:   Omayra Laucella       Title:   Vice President
      CAPITAL ONE, N.A.     By:   /s/ Wesley Fontana       Name:   Wesley
Fontana       Title:   Vice President       CITIBANK, N.A.     By:   /s/ John F.
Miller       Name:   John F. Miller       Title:   Attorney-In-Fact       AMEGY
BANK NATIONAL ASSOCIATION     By:   /s/ Charles W. Patterson       Name:  
Charles W. Patterson       Title:   Senior Vice President       NATIXIS     By:
  /s/ Liana Tchernysheva       Name:   Liana Tchernysheva       Title:  
Director     By:   /s/ Donovan Broussard       Name:   Donovan Broussard      
Title:   Managing Director

First Amendment – Fourth Amended and Restated Senior Revolving Credit Agreement

Signature Page

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LENDERS:     BANK OF TEXAS, N.A.     By:   /s/ Mari Salazar       Name:   Mari
Salazar       Title:   Vice President       ALLIED IRISH BANK p.l.c.     By:  
/s/ Edward Fenk       Name:   Edward Fenk       Title:   Vice President     By:
  /s/ James Giordano       Name:   James Giordano       Title:   AVP      
MUZUHO CORPORATE BANK, LTD.     By:   /s/ Leon Mo       Name:   Leon Mo      
Title:   Authorized Signatory

First Amendment – Fourth Amended and Restated Senior Revolving Credit Agreement

Signature Page

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ANNEX I

LIST OF MAXIMUM CREDIT AMOUNTS

Aggregate Maximum Credit Amounts

 

Name of Lender

   Applicable
Percentage     Maximum
Credit Amount

BNP Paribas*

   9.50 %    $ 190,000,000

Bank of America, N.A.*

   7.50 %    $ 150,000,000

Bank of Montreal*

   7.50 %    $ 150,000,000

JP Morgan Chase Bank, N.A.*

   7.50 %    $ 150,000,000

Wells Fargo Bank, N.A.*

   7.50 %    $ 150,000,000

Royal Bank of Canada*

   7.50 %    $ 150,000,000

Barclays Bank PLC*

   7.50 %    $ 150,000,000

Morgan Stanley Bank, N.A.*

   7.50 %    $ 150,000,000

Credit Agricole CIB*

   6.33 %    $ 126,666,667

Credit Suisse, Cayman Islands Branch*

   6.33 %    $ 126,666,667

Deutsche Bank Trust Company Americas

   6.33 %    $ 126,666,667

Capital One, N.A.

   4.67 %    $ 93,333,333

Citibank, N.A.

   2.67 %    $ 53,333,333

Amegy Bank National Association

   2.67 %    $ 53,333,333

Natixis

   2.37 %    $ 47,333,333

Bank of Texas, N.A.

   2.33 %    $ 46,666,667

Allied Irish Bank p.l.c.

   2.30 %    $ 46,000,000

Mizuho Corporate Bank, Ltd.

   2.00 %    $ 40,000,000

TOTAL

   100 %    $ 2,000,000,000

 

* Adjusting Lender

 

ANNEX I