Petrohawk and KCS Provide Merger Update; Companies Clear Regulatory Hurdle, Increase Hedge Position and Look Forward to July 12

Petrohawk Energy Corporation (NASDAQ:HAWK) ("Petrohawk")
and KCS Energy, Inc. (NYSE:KCS) ("KCS") today announced the June 19,
2006 expiration of the waiting period for U.S. antitrust review under
the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended,
in connection with the previously announced proposed merger of
Petrohawk and KCS. The expiration of the Hart-Scott-Rodino waiting
period satisfies one of the conditions to the merger. Consummation of
the merger remains subject to other customary closing conditions,
including approval of the merger by the stockholders of both
companies. Proxy statements were mailed to stockholders on June 5,
2006 in advance of stockholders' meetings to be held by both Petrohawk
and KCS on July 12, 2006.
   In addition, Petrohawk announced that over approximately 75% in
principal amount as of 5:00 p.m. EDT, of its outstanding 9 7/8% Senior
Notes due 2011 have been tendered along with related consents in
connection with its cash tender offer to purchase any and all of the
outstanding $124,490,000 aggregate principal amount of its Notes. The
tender offer and consent solicitation are being made pursuant to the
terms and subject to the conditions set forth in an Offer to Purchase
and Consent Solicitation Statement from Petrohawk dated June 8, 2006,
as amended earlier this week, and a consent and letter of transmittal,
which have more details including a description of the terms of the
tender offer and consent solicitation. The tender offer is scheduled
to expire at 5:00 p.m. EDT on July 10, 2006, unless extended. The
consent date is today, June 22, 2006. Holders must tender their Notes
and deliver their consents by 5:00 p.m. EDT, unless extended by
Petrohawk, to qualify for payment of total consideration for the
Notes, which includes the consent payment.
   Petrohawk also announced today that it has entered into derivative
contracts covering 20,000 MMbtu/day of production for calendar year
2007. The contracts are in the form of costless collars with an
average floor price of $7.50/MMbtu and an average ceiling price of
$12.87/MMbtu. KCS announced that it has entered into costless collars
covering 13,740 MMbtu/day of production for calendar year 2007 with an
average floor price of $7.45/MMbtu and an average ceiling price of
$12.89/MMbtu. Petrohawk and KCS currently plan to continue to
periodically put additional hedges in place in order to reach a
desired hedging level for the combined companies of approximately 50%
of anticipated production for 2007.
   Petrohawk and KCS also indicated they have received inquiries
regarding whether their proposed merger will constitute a change of
control with respect to the indenture governing the KCS 7 1/8% Senior
Notes due 2012, entitling the holders to put them to the issuer at
101%. After reviewing the substance of these inquiries, Petrohawk and
KCS, after consultation with counsel, continue to believe there will
be no such change of control, as supported by the calculation of the
number of Petrohawk common shares expected to be issued to KCS
stockholders in the merger and other relevant factors.
   Petrohawk and KCS announced their proposed merger on April 21,
2006, which, upon closing, will have the effect of creating a leading
onshore oil and gas producer with an enterprise value of approximately
$3.5 billion. On a pro forma basis, the Company will have
approximately one trillion cubic feet of natural gas equivalents
(Tcfe) of proved reserves with current production of approximately 300
MMcfe/day, of which approximately 68% would be classified as proved
developed and approximately 77% would be natural gas, and
approximately 3 Tcfe of non-proved reserve potential in its inventory.
   This press release does not constitute an offer to purchase or a
solicitation of acceptance of the tender offer, which may be made only
pursuant to the terms of the Offer to Purchase and Consent
Solicitation Statement and related consent and letter of transmittal.
In any jurisdiction where the laws require the tender offers to be
made by a licensed broker or dealer, the tender offer shall be deemed
made on behalf of Petrohawk by Credit Suisse or one or more registered
brokers or dealers under the laws of such jurisdiction.
   Petrohawk Energy Corporation is an independent oil and gas company
engaged in the acquisition, development, production and exploration of
natural oil and gas properties located in North America. Petrohawk's
properties are concentrated in the East Texas/North Louisiana, Gulf
Coast, South Texas, Permian Basin, Anadarko and Arkoma regions.
   KCS is an independent oil and gas company engaged in the
acquisition, exploration, development and production of natural gas
and oil properties primarily located in the Mid-Continent and onshore
Gulf Coast regions of the United States. KCS also has interests in
producing properties in Michigan, California, Wyoming and offshore
Gulf of Mexico.
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For more information please refer to Petrohawk's and/or KCS's
websites or contact:

For Petrohawk:

Shane M. Bayless        or      Joan Dunlap
[phone]                  [phone] 
[e-mail]          [e-mail]


For KCS Energy:

Jim Christmas
[phone]
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   Additional Information for Investors

   This press release contains forward-looking information regarding
Petrohawk and KCS that is intended to be covered by the safe harbor
"forward-looking statements" provided by the Private Securities
Litigation Reform Act of 1995. All statements included in this press
release that address activities, events or developments that Petrohawk
and KCS expect, believe or anticipate will or may occur in the future
are forward-looking statements. These often, but not always, are
identified by using words such as "expects", "anticipates", "plans",
"estimates", "potential", "possible", "probable", or "intends", or
stating that certain actions, events or results "may", "will",
"should", or "could" be taken, occur or be achieved). Forward-looking
statements are based on current expectations, estimates and
projections that involve a number of risks and uncertainties, which
could cause actual results to differ materially from those reflected
in the statements. These risks include, but are not limited to the
possibility that the companies may be unable to obtain stockholder or
other approvals required for the merger Additional information on
risks and other factors which could affect either companies'
operations or financial results are included in the companies' other
reports on file with the United States Securities and Exchange
Commission. Forward-looking statements are based on the estimates and
opinions of both companies' management at the time the statements are
made. Neither Petrohawk nor KCS assume any obligation to update
forward-looking statements should circumstances or management's
estimates or opinions change.

   Additional Information About the Transaction and Where to Find It:

   Petrohawk has filed a registration statement on Form S-4
(Registration Number 333-134235) with the SEC that contains a
prospectus and a joint proxy statement regarding the proposed
transaction. Investors and security holders of Petrohawk and KCS are
urged to read the definitive joint proxy statement/prospectus and any
other relevant materials filed with the SEC, as well as any amendments
or supplements to those documents, because they will contain important
information about Petrohawk, KCS and the proposed transaction.
Investors and security holders may obtain these documents free of
charge at the SEC's website at www.sec.gov. In addition, materials
filed with the SEC by Petrohawk may be obtained free of charge from
Petrohawk's website at www.petrohawk.com. Materials filed with the SEC
by KCS may be obtained free of charge from KCS's website at
www.kcsenergy.com.
   Petrohawk, KCS and their respective executive officers and
directors may be deemed to be participants in the solicitation of
proxies from the stockholders of Petrohawk and KCS in favor of the
proposed transaction. Information about the executive officers and
directors of Petrohawk and their direct or indirect interests, by
security holdings or otherwise, in the proposed transaction are set
forth in the joint proxy statement/prospectus relating to the proposed
transaction. Information about the executive officers and directors of
KCS and Petrohawk and their direct or indirect interests, by security
holdings or otherwise, in the proposed transaction are set forth in
the joint proxy statement/prospectus relating to the proposed
transaction.