Document:

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                                                                    Exhibit 10.1

                                VOTING AGREEMENT

     This Voting Agreement (this "AGREEMENT") is dated as of April 20, 2006, by
and among Petrohawk Energy Corporation ("PETROHAWK"), KCS Energy, Inc., a
Delaware corporation ("KCS"), and _____________ (the "STOCKHOLDER").

     WHEREAS, Stockholder desires that Petrohawk, Hawk Nest Corporation, a
Delaware corporation and wholly-owned subsidiary of Petrohawk ("PURCHASER"), and
KCS enter into the Agreement and Plan of Merger dated the date hereof (the
"MERGER AGREEMENT"; undefined capitalized terms herein are defined in the Merger
Agreement) providing for the merger of Purchaser with and into KCS and for the
merger of KCS with and into Parent (the "MERGER") upon the terms and subject to
the conditions set forth in the Merger Agreement;

     WHEREAS, Stockholder is executing this Agreement as an inducement to KCS to
enter into and execute the Merger Agreement (and this Agreement shall not be
effective until the parties to the Merger Agreement execute the Merger
Agreement); and

     NOW, THEREFORE, in consideration of the execution and delivery by KCS of
the Merger Agreement and the mutual covenants, conditions and agreements
contained herein and therein, the parties agree as follows:

     1. Representations and Warranties.

     (a)  Stockholder represents and warrants to KCS as follows:

          (i) Stockholder is the record and beneficial owner of that number of
     shares of capital stock of Petrohawk set forth opposite its name on
     Schedule A (together with any other shares of other capital stock of
     Petrohawk acquired after the date hereof, including through the exercise of
     any stock options, warrants or similar instruments, being collectively
     referred to herein as the "SUBJECT SHARES") and the other securities
     exercisable or exchangeable for such capital stock listed on Schedule A
     (the "OTHER SECURITIES" and, together with the Subject Shares, the "COVERED
     SECURITIES"). Stockholder has the sole right to vote and Transfer (as
     defined herein) the Covered Securities set forth opposite its name on
     Schedule A, and none of such Covered Securities is subject to any voting
     trust or other agreement, arrangement or restriction with respect to the
     voting or the Transfer of the Subject Shares, except (A) as provided by
     this Agreement (it being understood that any pledge of the Pledged Shares
     (as defined below) shall not be a breach of this representation) and (B)
     those arising under applicable securities laws. Stockholder has all
     requisite power and authority, and the legal capacity, to enter into this
     Agreement and to perform its obligations hereunder. This Agreement has been
     duly executed and delivered by, and constitutes a valid and binding
     agreement of, Stockholder, enforceable against Stockholder in accordance
     with its terms, except as enforcement may be limited by or subject to the
     effects of bankruptcy, insolvency, reorganization, moratorium and other
     laws relating to or affecting the rights of creditors and of general
     principles of equity.

<PAGE>

          (ii) Neither the execution and delivery of this Agreement nor the
     performance by Stockholder of its obligations hereunder will result in a
     violation of, or a default under, or conflict with any contract, trust,
     commitment, agreement, understanding, arrangement or restriction of any
     kind (other than as may relate to the Pledged Shares but subject to the
     proviso set forth in (iv) below) to which Stockholder is a party or bound
     or to which the Covered Securities are subject, except as would not
     prevent, delay or otherwise materially impair Stockholder's ability to
     perform its obligations hereunder. Execution, delivery and performance of
     this Agreement by Stockholder will not violate, or require any consent,
     approval or notice under, any provision of any judgment, order, decree,
     statute, law, rule or regulation applicable to Stockholder or the Covered
     Securities, except (x) for any reports under Sections 13(d) of the Exchange
     Act as may be required in connection with this Agreement and the
     transactions contemplated hereby or (y) as would not reasonably be expected
     to prevent, delay or otherwise materially impair Stockholder's ability to
     perform its obligations hereunder.

          (iii) If Stockholder is married and the Covered Securities of
     Stockholder constitute community property or spousal approval is otherwise
     required for this Agreement to be legal, valid and binding, then, to the
     extent so required, this Agreement has been duly authorized, executed and
     delivered by, and constitutes a valid and binding agreement of,
     Stockholder's spouse, enforceable against such spouse in accordance with
     its terms, subject to the effects of bankruptcy, insolvency,
     reorganization, moratorium and other laws relating to or affecting the
     rights of creditors and of general principles of equity.

          (iv) The Covered Securities and the certificates representing such
     Covered Securities are held by Stockholder, or by a nominee or custodian
     for the benefit of Stockholder, free and clear of all liens, claims,
     security interests, proxies, voting trusts or agreements, understandings or
     arrangements or any other encumbrances whatsoever, except for (A) any such
     encumbrances arising hereunder, or (B) any such encumbrances arising
     pursuant to the pledge of any Covered Securities by Stockholder to a
     financial institution or a brokerage firm (the "PLEDGED SHARES"); provided,
     however, that Stockholder represents that any such arrangement regarding
     such Pledged Shares shall not prevent, delay or otherwise materially impair
     Stockholder's ability to execute and deliver this Agreement or perform its
     obligations hereunder, and Stockholder shall use its reasonable efforts to
     obtain an acknowledgment by the pledgee of the terms of this Agreement and
     such pledgee's agreement to vote the Pledged Shares (if and to the extent
     the voting power of the Pledged Shares is being or to be exercised by
     pledgee) in accordance with Section 2.

          (v) Except as disclosed in the Merger Agreement, no broker, investment
     banker, financial advisor or other person is entitled to any broker's,
     finder's, financial advisor's or other similar fee or commissions based
     upon arrangements made by or on behalf of Stockholder in connection with
     its entering into this Agreement. Stockholder shall have no obligation or
     liability of any kind with respect to any fee, commissions or other amount
     of any kind incurred or payable by or on behalf of Petrohawk or KCS in
     connection with the Merger.

                                        2

<PAGE>

          (vi) Stockholder understands and acknowledges that KCS is entering
     into the Merger Agreement in reliance upon Stockholder's execution and
     delivery of this Agreement. KCS and Petrohawk understand and acknowledge
     that Stockholder is entering into this Agreement in reliance upon
     Petrohawk's and KCS's execution and delivery of the Merger Agreement and
     intended consummation of the Merger.

     (b)  Petrohawk represents and warrants to Stockholder and KCS that:

          (i) The execution and delivery of this Agreement and the Merger
     Agreement (the "TRANSACTION DOCUMENTS") by Petrohawk and the performance by
     Petrohawk of its obligations thereunder and the consummation of the
     transactions contemplated thereby have been duly authorized by all
     necessary action on the part of Petrohawk. Each of the Transaction
     Documents has been duly executed and delivered by, and constitutes a valid
     and binding agreement of, Petrohawk, enforceable against Petrohawk in
     accordance with its terms, except as enforcement may be limited by or
     subject to the effects of bankruptcy, insolvency, reorganization,
     moratorium and other laws relating to or affecting the rights of creditors
     and of general principles of equity.

          (ii) Neither the execution and delivery of the Transaction Documents
     nor the performance by Petrohawk of its obligations thereunder will result
     in a violation of, or a default under, or conflict with, (A) any provision
     of its certificate of incorporation, bylaws, partnership agreement, limited
     liability company agreement or similar organizational documents, (B) any
     contract, trust, commitment, agreement, understanding, arrangement or
     restriction of any kind to which Petrohawk is a party or bound, except, in
     the case of clause (B), as would not prevent, delay or otherwise materially
     impair Petrohawk's ability to perform its obligations thereunder or
     consummate the Merger. Execution, delivery and performance of the
     Transaction Documents by Petrohawk will not violate, or require any
     consent, approval or notice under, any provision of any judgment, order,
     decree, statute, law, rule or regulation applicable to Petrohawk or the
     Covered Securities, except (x) for any reports under Sections 13(d) of the
     Exchange Act as may be required in connection with this Agreement and the
     transactions contemplated hereby or (y) as would not reasonably be expected
     to prevent, delay or otherwise materially impair Petrohawk's ability to
     perform its obligations thereunder or consummate the Merger.

          (iii) There is no action, claim, suit, demand, hearing, notice of
     violation or deficiency, or proceeding (including any investigation or
     partial proceeding, such as a deposition), domestic or foreign, pending, or
     to the knowledge of Petrohawk threatened, that could prevent the
     consummation of, materially impair or materially delay the Merger or any of
     the transactions contemplated hereby.

     (c)  KCS represents and warrants to Stockholder and Petrohawk that:

          (i) The execution and delivery of the Transaction Documents by KCS and
     the performance by KCS of its obligations thereunder and consummation of
     the transactions contemplated thereby have been duly authorized by all
     necessary action on the part of KCS. Each of the Transaction Documents has
     been duly executed and delivered by, and

                                        3

<PAGE>

     constitutes a valid and binding agreement of, KCS, enforceable against KCS
     in accordance with its terms, except as enforcement may be limited by or
     subject to the effects of bankruptcy, insolvency, reorganization,
     moratorium and other laws relating to or affecting the rights of creditors
     and of general principles of equity.

          (ii) Neither the execution and delivery of the Transaction Documents
     nor the performance by KCS of its obligations thereunder will result in a
     violation of, or a default under, or conflict with, (A) any provision of
     its certificate of incorporation or bylaws, (B) any contract, agreement or
     other legally binding instrument or obligation to which KCS is a party or
     bound, except in the case of clause (B), as would not be reasonably likely
     to have or result in a Material Adverse Effect on the Company or prevent or
     delay or otherwise materially impair KCS's ability to perform its
     obligations thereunder or consummate the Merger. Execution, delivery and
     performance of the Transaction Documents by KCS will not violate or
     conflict with any provision of any judgment, order, decree, statute, law,
     rule or regulation applicable to KCS or the Covered Securities, except (x)
     for any reports under Sections 13(d) of the Exchange Act as may be required
     in connection with this Agreement and the transactions contemplated hereby
     or (y) as would not be reasonably likely to have or result in a Material
     Adverse Effect on the Company or would not be reasonably likely to prevent,
     delay or otherwise materially impair KCS's ability to perform its
     obligations thereunder or consummate the Merger.

          (iii) There is no Litigation pending, or to the Knowledge of KCS,
     threatened that would prevent the consummation of, materially impair or
     materially delay the Merger or any of the transactions contemplated hereby.

     (d)  Petrohawk and KCS each represent and warrant to Stockholder that:

          (i) Other than the voting agreements of even date herewith between
     Petrohawk, KCS and the persons identified on Schedule B (the "OTHER SUPPORT
     AGREEMENTS"), Stockholder and others, a form of which agreements are, or
     will be, publicly filed, it is not a party to any agreement or
     understanding with any stockholder with respect to shares of capital stock
     of Petrohawk.

          (ii) The Other Support Agreements contain terms and conditions
     substantially the same as and no more or less favorable to any other
     stockholder party thereto than those contained in this Agreement.

          (iii) Entering into this Agreement and the Other Support Agreements
     shall not result in any adverse consequence to the Stockholder under
     Section 203 of the DGCL, or any similar protective provisions of the DGCL.

          (iv) To our Knowledge, no filings of any kind (other than a Schedule
     13D under the Exchange Act reflecting this Agreement and any such Other
     Support Agreement) shall be required to be filed by Stockholder or any such
     other stockholders in connection with the entering into of this Agreement
     or the Other Support Agreements or the consummation of the Merger,
     including, without limitation, any Section 16 filings under the Exchange
     Act.

                                        4

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     2. Voting Agreements. During the Term (as defined below) of this Agreement,
at any meeting of stockholders of Petrohawk or at any adjournment thereof or in
any other circumstances upon which a vote, consent or other approval (including
by written consent) relating to the Merger is sought, Stockholder shall,
including by executing a written consent solicitation if requested by KCS, vote
(or cause to be voted) the Subject Shares: in favor of the Merger, the adoption
by Petrohawk of the Merger Agreement and the approval of the terms thereof and
each of the other transactions contemplated by the Merger.

     3. Irrevocable Proxy. Stockholder hereby appoints KCS as its proxy to vote
all of the Stockholder's Subject Shares at any meeting of stockholders of
Petrohawk (including any adjournments and postponements thereof) on the matters
described in Section 2, and to execute and deliver any written consents to
fulfill such Stockholder's obligations under this Agreement. This proxy is
coupled with an interest and is irrevocable until the end of the Term, at which
time it shall terminate.

     4. Revocation of Other Proxies. To the extent inconsistent with the other
provisions of this Agreement or the Merger Agreement, Stockholder hereby revokes
any and all previous proxies with respect to the Subject Shares.

     5. Other Covenants. Stockholder agrees with, and covenants to, KCS during
the Term of this Agreement as follows:

          (a) Stockholder shall not after the date hereof (i) sell, transfer,
     pledge, assign or otherwise dispose of (including by gift) (collectively,
     "TRANSFER"), or consent to any Transfer of, any Covered Securities or any
     interest therein, except pursuant to the Merger, (ii) enter into any
     contract, option or other agreement with respect to any Transfer of any or
     all of the Covered Securities or any interest therein, (iii) grant any
     proxy, power-of-attorney or other authorization in or with respect to the
     Subject Shares or (iv) deposit the Subject Shares into a voting trust or
     enter into a voting agreement or voting arrangement with respect to the
     Subject Shares; provided, that Stockholder may Transfer any of the Covered
     Securities to an affiliate of Stockholder or pursuant to any bona fide
     charitable gift or by will or applicable laws of descent and distribution,
     or for estate planning purposes (provided such transferee evidences in a
     writing reasonably satisfactory to the other parties hereto such
     transferee's agreement to the terms hereof) or any other person or entity
     who is on the date hereof or hereafter becomes a party to a similar
     agreement; provided, further, that the restrictions in this Section 5 shall
     not be deemed violated by any Transfer of Covered Securities pursuant to a
     cashless exercise of stock options or warrants; and provided, further, that
     a pledge of Pledged Shares made in accordance with Section 1(a)(iv) shall
     not be deemed to be a violation of the restrictions in this Section 5.

          (b) Stockholder hereby waives any rights of appraisal, or rights to
     dissent from the Merger, that such Stockholder may have.

     6. Certain Events. This Agreement and the obligations hereunder shall,
during the Term hereof, attach to Stockholder's Covered Securities and shall be
binding upon any Person to which legal or beneficial ownership of such Shares
shall pass, whether by operation of law or

                                        5

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otherwise, including Stockholder's administrators or successors. In the event of
any stock split, stock dividend, merger, reorganization, recapitalization or
other change in the capital structure of Petrohawk affecting the Covered
Securities or the acquisition of additional shares of Covered Securities or
other voting securities of Petrohawk by Stockholder, the number of Covered
Securities listed on Schedule A beside the name of Stockholder shall be adjusted
appropriately, and this Agreement and the obligations hereunder shall attach to
any additional Covered Securities or other voting securities of Petrohawk issued
to or acquired by Stockholder.

     7. Stop Transfer. Petrohawk shall not register the transfer of any
certificate representing any Covered Securities during the Term hereof, unless
such transfer is made to Petrohawk or otherwise in compliance with this
Agreement.

     8. Stockholder Capacity. No person executing this Agreement (or an
affiliate thereof) who is or becomes during the Term a director of Petrohawk
makes any agreement or understanding herein in his capacity as such director.
Stockholder signs solely in its capacity as the record and beneficial owner of,
or the trustee of a trust whose beneficiaries are the beneficial owners of,
Stockholder's Covered Securities.

     9. Further Assurances. Stockholder shall, upon request of KCS, execute and
deliver any additional documents and take such further actions as may reasonably
be deemed by KCS to be necessary or desirable to carry out the provisions
hereof.

     10. Termination. This Agreement, and all rights and obligations of the
parties hereunder, shall commence upon the execution of the Merger Agreement as
contemplated above and terminate upon (and shall only be effective from the date
hereof until) the first to occur of (i) the Effective Time, (ii) the date upon
which the Merger Agreement is terminated in accordance with its terms, (iii) the
mutual consent of KCS and Stockholder, (iv) the date of any amendment, waiver or
modification to the Merger Agreement in a manner that reduces the Merger
Consideration or otherwise materially adversely affects the Stockholder, or (v)
December 31, 2006 (such period from the date hereof until such termination is
referred to herein as the "TERM")

     11. Miscellaneous.

     (a) All notices, requests, claims, demands and other communications under
this Agreement shall be in writing and shall be deemed given if delivered
personally or sent by overnight courier (providing proof of delivery) to the
parties at the following addresses (or at such other address for a party as
shall be specified by like notice): (i) if to Petrohawk or KCS, to the
appropriate address set forth in Section 8.4 of the Merger Agreement; and (ii)
if to Stockholder, to the appropriate address set forth on Schedule A.

     (b) Each party to this Agreement ("Party") submits to the jurisdiction of
any state or federal court sitting in the State of Delaware in any dispute or
action arising out of or relating to this Agreement and agrees that all claims
in respect of such dispute or action may be heard and determined in any such
court. Each Party also agrees not to bring any dispute or action arising out of
or relating to this Agreement in any other court. Each Party agrees that a final
judgment in any dispute or action so brought will be conclusive and may be
enforced by action on the judgment or in any other manner provided at law
(common, statutory or other) or in equity. Each

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<PAGE>

Party waives any defense of inconvenient forum to the maintenance of any dispute
or action so brought and waives any bond, surety, or other security that might
be required of any other Party with respect thereto.

     (c) The headings contained in this Agreement are for reference purposes
only and shall not affect in any way the meaning or interpretation of this
Agreement.

     (d) This Agreement may be executed in two or more counterparts, all of
which shall be considered one and the same agreement and shall become effective
as to Stockholder when one or more counterparts have been signed by each of
Petrohawk, KCS and Stockholder and delivered to Petrohawk, KCS and Stockholder.

     (e) Other than the Merger Agreement and the Confidentiality Agreement, this
Agreement (including the documents and instruments referred to herein)
constitutes the entire agreement, and supersedes all prior agreements and
understandings, both written and oral, among the parties with respect to the
subject matter hereof, and this Agreement is not intended to confer upon any
other person (other than Purchaser) any rights or remedies hereunder.

     (f) This Agreement shall be governed by, construed and enforced in
accordance with, the laws of the State of Delaware, without giving effect to the
principles of conflicts of laws thereof.

     (g) Neither this Agreement nor any of the rights, interests or obligations
under this Agreement shall be assigned, in whole or in part, by operation of law
or otherwise, by any of the parties without the prior written consent of the
other parties, except that Stockholder may transfer Covered Securities to the
extent permitted by Section 5(a) of this Agreement. Any assignment in violation
of the foregoing shall be void.

     (h) As between Stockholder and KCS, each of such Parties agrees that
irreparable damage to the other, non-breaching party would occur and that such
non-breaching party would not have any adequate remedy at law in the event that
any of the provisions of this Agreement were not performed in accordance with
their specific terms or were otherwise breached. It is accordingly agreed that
the non-breaching party shall be entitled to an injunction or injunctions to
prevent breaches by the other party of this Agreement and to enforce
specifically the terms and provisions of this Agreement, this being in addition
to any other remedy to which it may be entitled at law or in equity.

     (i) If any term, provision, covenant or restriction herein, or the
application thereof to any circumstance, shall, to any extent, be held by a
court of competent jurisdiction to be invalid, void or unenforceable, the
remainder of the terms, provisions, covenants and restrictions herein and the
application thereof to any other circumstances shall remain in full force and
effect, shall not in any way be affected, impaired or invalidated, and shall be
enforced to the fullest extent permitted by law.

     (j) No amendment, modification or waiver in respect of this Agreement shall
be effective against any Party unless it shall be in writing and signed by such
Party.

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<PAGE>

     IN WITNESS WHEREOF, Petrohawk, KCS, and the Stockholder have caused this
Agreement to be duly executed and delivered as of the date first written above.

                                     Petrohawk Energy Corporation

                                     By:
                                         ---------------------------------------
                                     Name: Floyd C. Wilson
                                     Title: Chairman, President and
                                            Chief Executive Officer

                                     KCS Energy, Inc.

                                     By:
                                         ---------------------------------------
                                     Name: James W. Christmas
                                     Title: Chairman and Chief Executive Officer

                                     STOCKHOLDER:

                                     -------------------------------------------

                                     STOCKHOLDER SPOUSE:

                                     -------------------------------------------

<PAGE>

                                   SCHEDULE A

<TABLE>
<CAPTION>
                     NUMBER
                   OF SHARES
                   OF COMMON      NUMBER     NUMBER OF
NAME AND ADDRESS     STOCK     OF WARRANTS    OPTIONS
----------------   ---------   -----------   ---------
<S>                <C>         <C>           <C>

</TABLE>

<PAGE>

                                   SCHEDULE B

                                 Floyd C. Wilson
                                Stephen W. Herod
                                Shane M. Bayless
                                  Larry L. Helm
                             Richard K. Stoneburner<PAGE>

                                                                    Exhibit 10.2

                                VOTING AGREEMENT

     This Voting Agreement (this "AGREEMENT") is dated as of April 20, 2006, by
and among Petrohawk Energy Corporation ("PETROHAWK"), KCS Energy, Inc., a
Delaware corporation ("KCS"), and _____________________ (the "STOCKHOLDER").

     WHEREAS, Stockholder desires that Petrohawk, Hawk Nest Corporation, a
Delaware corporation and wholly-owned subsidiary of Petrohawk ("PURCHASER"), and
KCS enter into the Agreement and Plan of Merger dated the date hereof (the
"MERGER AGREEMENT"; undefined capitalized terms herein are defined in the Merger
Agreement) providing for the merger of Purchaser with and into KCS and for the
merger of KCS with and into Parent (the "MERGER") upon the terms and subject to
the conditions set forth in the Merger Agreement;

     WHEREAS, Stockholder is executing this Agreement as an inducement to
Petrohawk to enter into and execute the Merger Agreement (and this Agreement
shall not be effective until the parties to the Merger Agreement execute the
Merger Agreement); and

     WHEREAS, the Board of Directors of KCS has adopted such resolutions as are
necessary so that the provisions of Section 203 of the DGCL are inapplicable to
the execution and performance of this Agreement;

     NOW, THEREFORE, in consideration of the execution and delivery by Petrohawk
of the Merger Agreement and the mutual covenants, conditions and agreements
contained herein and therein, the parties agree as follows:

     1.   Representations and Warranties.

     (a)  Stockholder represents and warrants to Petrohawk as follows:

          (i) Stockholder is the record and beneficial owner of that number of
     shares of capital stock of KCS set forth opposite its name on Schedule A
     (together with any other shares of other capital stock of KCS acquired
     after the date hereof, including through the exercise of any stock options,
     warrants or similar instruments, being collectively referred to herein as
     the "SUBJECT SHARES") and the other securities exercisable or exchangeable
     for such capital stock listed on Schedule A (the "OTHER SECURITIES" and,
     together with the Subject Shares, the "COVERED SECURITIES"). Stockholder
     has the sole right to vote and Transfer (as defined herein) the Covered
     Securities set forth opposite its name on Schedule A, and none of such
     Covered Securities is subject to any voting trust or other agreement,
     arrangement or restriction with respect to the voting or the Transfer of
     the Subject Shares, except (A) as provided by this Agreement (it being
     understood that any pledge of the Pledged Shares (as defined below) shall
     not be a breach of this representation), (B) those arising under applicable
     securities laws and (C) Stockholder shall be entitled to vote the Subject
     Shares with respect to the election of directors at KCS's annual meeting of
     stockholders to be held on May 25, 2006 (the "Annual Meeting"). Stockholder
     has all requisite power and authority, and the legal capacity, to enter
     into this Agreement and to perform its obligations hereunder. This
     Agreement has been duly executed and delivered by, and constitutes a valid
     and binding agreement of, Stockholder, enforceable against Stockholder in
     accordance with its terms, except as

<PAGE>

     enforcement may be limited by or subject to the effects of bankruptcy,
     insolvency, reorganization, moratorium and other laws relating to or
     affecting the rights of creditors and of general principles of equity.

          (ii) Neither the execution and delivery of this Agreement nor the
     performance by Stockholder of its obligations hereunder will result in a
     violation of, or a default under, or conflict with any contract, trust,
     commitment, agreement, understanding, arrangement or restriction of any
     kind (other than as may relate to the Pledged Shares but subject to the
     proviso set forth in (iv) below) to which Stockholder is a party or bound
     or to which the Covered Securities are subject, except as would not
     prevent, delay or otherwise materially impair Stockholder's ability to
     perform its obligations hereunder. Execution, delivery and performance of
     this Agreement by Stockholder will not violate, or require any consent,
     approval or notice under, any provision of any judgment, order, decree,
     statute, law, rule or regulation applicable to Stockholder or the Covered
     Securities, except (x) for any reports under Sections 13(d) of the Exchange
     Act as may be required in connection with this Agreement and the
     transactions contemplated hereby or (y) as would not reasonably be expected
     to prevent, delay or otherwise materially impair Stockholder's ability to
     perform its obligations hereunder.

          (iii) If Stockholder is married and the Covered Securities of
     Stockholder constitute community property or spousal approval is otherwise
     required for this Agreement to be legal, valid and binding, then, to the
     extent so required, this Agreement has been duly authorized, executed and
     delivered by, and constitutes a valid and binding agreement of,
     Stockholder's spouse, enforceable against such spouse in accordance with
     its terms, subject to the effects of bankruptcy, insolvency,
     reorganization, moratorium and other laws relating to or affecting the
     rights of creditors and of general principles of equity.

          (iv) The Covered Securities and the certificates representing such
     Covered Securities are held by Stockholder, or by a nominee or custodian
     for the benefit of Stockholder, free and clear of all liens, claims,
     security interests, proxies, voting trusts or agreements, understandings or
     arrangements or any other encumbrances whatsoever, except for (A) any such
     encumbrances arising hereunder, (B) Stockholder may vote the Subject Shares
     in connection with the election of directors at the Annual Meeting, or (C)
     any such encumbrances arising pursuant to the pledge of any Covered
     Securities by Stockholder to a financial institution or a brokerage firm
     (the "PLEDGED SHARES"); provided, however, that Stockholder represents that
     any such arrangement regarding such Pledged Shares shall not prevent, delay
     or otherwise materially impair Stockholder's ability to execute and deliver
     this Agreement or perform its obligations hereunder, and Stockholder shall
     use its reasonable efforts to obtain an acknowledgment by the pledgee of
     the terms of this Agreement and such pledgee's agreement to vote the
     Pledged Shares (if and to the extent the voting power of the Pledged Shares
     is being or to be exercised by pledgee) in accordance with Section 2.

          (v) Except as disclosed in the Merger Agreement, no broker, investment
     banker, financial advisor or other person is entitled to any broker's,
     finder's, financial advisor's or other similar fee or commissions based
     upon arrangements made by or on

                                       2

<PAGE>

     behalf of Stockholder in connection with its entering into this Agreement.
     Stockholder shall have no obligation or liability of any kind with respect
     to any fee, commissions or other amount of any kind incurred or payable by
     or on behalf of Petrohawk or KCS in connection with the Merger.

          (vi) Stockholder understands and acknowledges that Petrohawk is
     entering into the Merger Agreement in reliance upon Stockholder's execution
     and delivery of this Agreement. KCS and Petrohawk understand and
     acknowledge that Stockholder is entering into this Agreement in reliance
     upon Petrohawk's and KCS's execution and delivery of the Merger Agreement
     and intended consummation of the Merger.

     (b) Petrohawk represents and warrants to Stockholder and KCS that:

          (i) The execution and delivery of this Agreement and the Merger
     Agreement (the "TRANSACTION DOCUMENTS") by Petrohawk and the performance by
     Petrohawk of its obligations thereunder and the consummation of the
     transactions contemplated thereby have been duly authorized by all
     necessary action on the part of Petrohawk. Each of the Transaction
     Documents has been duly executed and delivered by, and constitutes a valid
     and binding agreement of, Petrohawk, enforceable against Petrohawk in
     accordance with its terms, except as enforcement may be limited by or
     subject to the effects of bankruptcy, insolvency, reorganization,
     moratorium and other laws relating to or affecting the rights of creditors
     and of general principles of equity.

          (ii) Neither the execution and delivery of the Transaction Documents
     nor the performance by Petrohawk of its obligations thereunder will result
     in a violation of, or a default under, or conflict with, (A) any provision
     of its certificate of incorporation, bylaws, partnership agreement, limited
     liability company agreement or similar organizational documents, (B) any
     contract, trust, commitment, agreement, understanding, arrangement or
     restriction of any kind to which Petrohawk is a party or bound, except, in
     the case of clause (B), as would not prevent, delay or otherwise materially
     impair Petrohawk's ability to perform its obligations thereunder or
     consummate the Merger. Execution, delivery and performance of the
     Transaction Documents by Petrohawk will not violate, or require any
     consent, approval or notice under, any provision of any judgment, order,
     decree, statute, law, rule or regulation applicable to Petrohawk or the
     Covered Securities, except (x) for any reports under Sections 13(d) of the
     Exchange Act as may be required in connection with this Agreement and the
     transactions contemplated hereby or (y) as would not reasonably be expected
     to prevent, delay or otherwise materially impair Petrohawk's ability to
     perform its obligations thereunder or consummate the Merger.

          (iii) There is no action, claim, suit, demand, hearing, notice of
     violation or deficiency, or proceeding (including any investigation or
     partial proceeding, such as a deposition), domestic or foreign, pending, or
     to the knowledge of Petrohawk threatened, that could prevent the
     consummation of, materially impair or materially delay the Merger or any of
     the transactions contemplated hereby.

     (c) KCS represents and warrants to Stockholder and Petrohawk that:

                                       3

<PAGE>

          (i) The execution and delivery of the Transaction Documents by KCS and
     the performance by KCS of its obligations thereunder and consummation of
     the transactions contemplated thereby have been duly authorized by all
     necessary action on the part of KCS. Each of the Transaction Documents has
     been duly executed and delivered by, and constitutes a valid and binding
     agreement of, KCS, enforceable against KCS in accordance with its terms,
     except as enforcement may be limited by or subject to the effects of
     bankruptcy, insolvency, reorganization, moratorium and other laws relating
     to or affecting the rights of creditors and of general principles of
     equity.

          (ii) Neither the execution and delivery of the Transaction Documents
     nor the performance by KCS of its obligations thereunder will result in a
     violation of, or a default under, or conflict with, (A) any provision of
     its certificate of incorporation or bylaws, (B) any contract, agreement or
     other legally binding instrument or obligation to which KCS is a party or
     bound, except in the case of clause (B), as would not be reasonably likely
     to have or result in a Material Adverse Effect on the Company or prevent or
     delay or otherwise materially impair KCS's ability to perform its
     obligations thereunder or consummate the Merger. Execution, delivery and
     performance of the Transaction Documents by KCS will not violate or
     conflict with any provision of any judgment, order, decree, statute, law,
     rule or regulation applicable to KCS or the Covered Securities, except (x)
     for any reports under Sections 13(d) of the Exchange Act as may be required
     in connection with this Agreement and the transactions contemplated hereby
     or (y) as would not be reasonably likely to have or result in a Material
     Adverse Effect on the Company or would not be reasonably likely to prevent,
     delay or otherwise materially impair KCS's ability to perform its
     obligations thereunder or consummate the Merger.

          (iii) There is no Litigation pending, or to the Knowledge of KCS,
     threatened that would prevent the consummation of, materially impair or
     materially delay the Merger or any of the transactions contemplated hereby.

     (d) Petrohawk and KCS each represent and warrant to Stockholder that:

          (i) Other than the voting agreements of even date herewith between
     Petrohawk, KCS and the persons identified on Schedule B (the "OTHER SUPPORT
     AGREEMENTS"), Stockholder and others, a form of which agreements are, or
     will be, publicly filed, it is not a party to any agreement or
     understanding with any stockholder with respect to shares of capital stock
     of KCS.

          (ii) The Other Support Agreements contain terms and conditions
     substantially the same as and no more or less favorable to any other
     stockholder party thereto than those contained in this Agreement.

          (iii) Entering into this Agreement and the Other Support Agreements
     shall not result in any adverse consequence to the Stockholder under
     Section 203 of the DGCL, or any similar protective provisions of the DGCL.

          (iv) To our Knowledge, no filings of any kind (other than a Schedule
     13D under the Exchange Act reflecting this Agreement and any such Other
     Support

                                       4

<PAGE>

     Agreement) shall be required to be filed by Stockholder or any such other
     stockholders in connection with the entering into of this Agreement or the
     Other Support Agreements or the consummation of the Merger, including,
     without limitation, any Section 16 filings under the Exchange Act.

     2. Voting Agreements. During the Term (as defined below) of this Agreement,
at any meeting of stockholders of KCS or at any adjournment thereof or in any
other circumstances upon which a vote, consent or other approval (including by
written consent) relating to the Merger is sought, Stockholder shall, including
by executing a written consent solicitation if requested by Petrohawk, vote (or
cause to be voted) the Subject Shares: (a) in favor of the Merger, the adoption
by KCS of the Merger Agreement and the approval of the terms thereof and each of
the other transactions contemplated by the Merger and (b) against any
transaction, agreement, matter or other Acquisition Proposal that would
reasonably be expected to impede, interfere with, delay, postpone or attempt to
discourage the Merger and the Merger Agreement.

     3. Irrevocable Proxy. Stockholder hereby appoints Petrohawk as its proxy to
vote all of the Stockholder's Subject Shares at any meeting of stockholders of
KCS (including any adjournments and postponements thereof) on the matters
described in Section 2, and to execute and deliver any written consents to
fulfill such Stockholder's obligations under this Agreement. This proxy is
coupled with an interest and is irrevocable until the end of the Term, at which
time it shall terminate.

     4. Revocation of Other Proxies. To the extent inconsistent with the other
provisions of this Agreement or the Merger Agreement, Stockholder hereby revokes
any and all previous proxies with respect to the Subject Shares.

     5. Other Covenants. Stockholder agrees with, and covenants to, Petrohawk
during the Term of this Agreement as follows:

     (a)  Stockholder shall not after the date hereof (i) sell, transfer,
          pledge, assign or otherwise dispose of (including by gift)
          (collectively, "Transfer"), or consent to any Transfer of, any Covered
          Securities or any interest therein, except pursuant to the Merger,
          (ii) enter into any contract, option or other agreement with respect
          to any Transfer of any or all of the Covered Securities or any
          interest therein, (iii) grant any proxy, power-of-attorney or other
          authorization in or with respect to the Subject Shares (except it is
          recognized that Stockholder may vote the Subject Shares in connection
          with the election of directors at the Annual Meeting) or (iv) deposit
          the Subject Shares into a voting trust or enter into a voting
          agreement or voting arrangement with respect to the Subject Shares;
          provided, that Stockholder may Transfer any of the Covered Securities
          to an affiliate of Stockholder or pursuant to any bona fide charitable
          gift or by will or applicable laws of descent and distribution, or for
          estate planning purposes (provided such transferee evidences in a
          writing reasonably satisfactory to the other parties hereto such
          transferee's agreement to the terms hereof) or any other person or
          entity who is on the date hereof or hereafter becomes a party to a
          similar agreement; provided, further, that the restrictions in this
          Section 5 shall not be deemed violated by any Transfer of Covered
          Securities pursuant to a cashless exercise of stock options or
          warrants; and provided, further,

                                       5

<PAGE>

          that a pledge of Pledged Shares made in accordance with Section
          1(a)(iv) shall not be deemed to be a violation of the restrictions in
          this Section 5.

     (b)  Stockholder hereby waives any rights of appraisal, or rights to
          dissent from the Merger, that such Stockholder may have.

     6. Certain Events. This Agreement and the obligations hereunder shall,
during the Term hereof, attach to Stockholder's Covered Securities and shall be
binding upon any Person to which legal or beneficial ownership of such Shares
shall pass, whether by operation of law or otherwise, including Stockholder's
administrators or successors. In the event of any stock split, stock dividend,
merger, reorganization, recapitalization or other change in the capital
structure of KCS affecting the Covered Securities or the acquisition of
additional shares of Covered Securities or other voting securities of KCS by
Stockholder, the number of Covered Securities listed on Schedule A beside the
name of Stockholder shall be adjusted appropriately, and this Agreement and the
obligations hereunder shall attach to any additional Covered Securities or other
voting securities of KCS issued to or acquired by Stockholder.

     7. Stop Transfer. KCS shall not register the transfer of any certificate
representing any Covered Securities during the Term hereof, unless such transfer
is made to Petrohawk or otherwise in compliance with this Agreement.

     8. Stockholder Capacity. No person executing this Agreement (or an
affiliate thereof) who is or becomes during the Term a director of KCS makes any
agreement or understanding herein in his capacity as such director. Stockholder
signs solely in its capacity as the record and beneficial owner of, or the
trustee of a trust whose beneficiaries are the beneficial owners of,
Stockholder's Covered Securities.

     9. Further Assurances. Stockholder shall, upon request of Petrohawk,
execute and deliver any additional documents and take such further actions as
may reasonably be deemed by Petrohawk to be necessary or desirable to carry out
the provisions hereof.

     10. Termination. This Agreement, and all rights and obligations of the
parties hereunder, shall commence upon the execution of the Merger Agreement as
contemplated above and terminate upon (and shall only be effective from the date
hereof until) the first to occur of (i) the Effective Time, (ii) the date upon
which the Merger Agreement is terminated in accordance with its terms, (iii) the
mutual consent of Petrohawk and Stockholder, (iv) the date of any amendment,
waiver or modification to the Merger Agreement in a manner that reduces the
Merger Consideration or otherwise materially adversely affects the Stockholder,
or (v) December 31, 2006 (such period from the date hereof until such
termination is referred to herein as the "TERM")

     11. Miscellaneous.

     (a) All notices, requests, claims, demands and other communications under
this Agreement shall be in writing and shall be deemed given if delivered
personally or sent by overnight courier (providing proof of delivery) to the
parties at the following addresses (or at such other address for a party as
shall be specified by like notice): (i) if to Petrohawk or KCS, to

                                       6

<PAGE>

the appropriate address set forth in Section 8.4 of the Merger Agreement; and
(ii) if to Stockholder, to the appropriate address set forth on Schedule A.

     (b) Each party to this Agreement ("Party") submits to the jurisdiction of
any state or federal court sitting in the State of Delaware in any dispute or
action arising out of or relating to this Agreement and agrees that all claims
in respect of such dispute or action may be heard and determined in any such
court. Each Party also agrees not to bring any dispute or action arising out of
or relating to this Agreement in any other court. Each Party agrees that a final
judgment in any dispute or action so brought will be conclusive and may be
enforced by action on the judgment or in any other manner provided at law
(common, statutory or other) or in equity. Each Party waives any defense of
inconvenient forum to the maintenance of any dispute or action so brought and
waives any bond, surety, or other security that might be required of any other
Party with respect thereto.

     (c) The headings contained in this Agreement are for reference purposes
only and shall not affect in any way the meaning or interpretation of this
Agreement.

     (d) This Agreement may be executed in two or more counterparts, all of
which shall be considered one and the same agreement and shall become effective
as to Stockholder when one or more counterparts have been signed by each of
Petrohawk, KCS and Stockholder and delivered to Petrohawk, KCS and Stockholder.

     (e) Other than the Merger Agreement and the Confidentiality Agreement, this
Agreement (including the documents and instruments referred to herein)
constitutes the entire agreement, and supersedes all prior agreements and
understandings, both written and oral, among the parties with respect to the
subject matter hereof, and this Agreement is not intended to confer upon any
other person (other than Purchaser) any rights or remedies hereunder.

     (f) This Agreement shall be governed by, construed and enforced in
accordance with, the laws of the State of Delaware, without giving effect to the
principles of conflicts of laws thereof.

     (g) Neither this Agreement nor any of the rights, interests or obligations
under this Agreement shall be assigned, in whole or in part, by operation of law
or otherwise, by any of the parties without the prior written consent of the
other parties, except that Stockholder may transfer Covered Securities to the
extent permitted by Section 5(a) of this Agreement. Any assignment in violation
of the foregoing shall be void.

     (h) As between Stockholder and Petrohawk, each of such Parties agrees that
irreparable damage to the other, non-breaching party would occur and that such
non-breaching party would not have any adequate remedy at law in the event that
any of the provisions of this Agreement were not performed in accordance with
their specific terms or were otherwise breached. It is accordingly agreed that
the non-breaching party shall be entitled to an injunction or injunctions to
prevent breaches by the other party of this Agreement and to enforce
specifically the terms and provisions of this Agreement, this being in addition
to any other remedy to which it may be entitled at law or in equity.

                                       7

<PAGE>

     (i) If any term, provision, covenant or restriction herein, or the
application thereof to any circumstance, shall, to any extent, be held by a
court of competent jurisdiction to be invalid, void or unenforceable, the
remainder of the terms, provisions, covenants and restrictions herein and the
application thereof to any other circumstances shall remain in full force and
effect, shall not in any way be affected, impaired or invalidated, and shall be
enforced to the fullest extent permitted by law.

     (j) No amendment, modification or waiver in respect of this Agreement shall
be effective against any Party unless it shall be in writing and signed by such
Party.

                            [SIGNATURE PAGE FOLLOWS]

                                       8

<PAGE>

     IN WITNESS WHEREOF, Petrohawk, KCS, and the Stockholder have caused this
Agreement to be duly executed and delivered as of the date first written above.

                                        Petrohawk Energy Corporation

                                        By:
                                            ------------------------------------
                                        Name: Floyd C. Wilson
                                        Title: Chairman, President and
                                               Chief Executive Officer

                                        KCS Energy, Inc.

                                        By:
                                            ------------------------------------
                                        Name: James W. Christmas
                                        Title: Chairman, President and
                                               Chief Executive Officer

                                        STOCKHOLDER:

                                        ----------------------------------------

                                        STOCKHOLDER SPOUSE:

                                        ----------------------------------------

<PAGE>

                                   SCHEDULE A

<TABLE>
<CAPTION>
                     NUMBER    NUMBER OF OPTIONS,
NAME AND ADDRESS   OF SHARES     WARRANTS, ETC.
----------------   ---------   ------------------
<S>                <C>         <C>

</TABLE>

<PAGE>

                                   SCHEDULE B

                               James W. Christmas
                                William N. Hahne
                                 Harry Lee Stout
                                 Joseph T. Leary

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