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   &lt;div align="left" style="font-size: 10pt; margin-top: 12pt"&gt;&lt;b&gt;15. Apache Merger&lt;/b&gt;
   &lt;/div&gt;
   &lt;div align="left" style="font-size: 10pt; margin-top: 6pt"&gt;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;On April&amp;#160;15, 2010, Mariner and Apache Corporation, a Delaware corporation (&amp;#8220;Apache&amp;#8221;),
   announced that they entered into a definitive agreement pursuant to which Apache will acquire
   Mariner in a stock and cash transaction. The Agreement and Plan of Merger dated April&amp;#160;14, 2010 (the
   &amp;#8220;Merger Agreement&amp;#8221;), by and among Apache, Mariner and ZMZ Acquisitions LLC, a Delaware limited
   liability company and wholly owned subsidiary of Apache (&amp;#8220;Merger Sub&amp;#8221;), contemplates a merger (the
   &amp;#8220;Merger&amp;#8221;) whereby Mariner will be merged with and into Merger Sub, with Merger Sub surviving the
   Merger as a wholly owned subsidiary of Apache.
   &lt;/div&gt;
   &lt;div align="left" style="font-size: 10pt; margin-top: 6pt"&gt;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;The total amount of cash and shares of Apache common stock that will be paid and issued,
   respectively, pursuant to the Merger Agreement is fixed, and Mariner stockholders will be entitled
   to receive (on an aggregate basis) 0.17043 of a share of Apache common stock, par value $0.625 per
   share, and $7.80 in cash for each share of Mariner common stock (the &amp;#8220;Mixed Consideration&amp;#8221;).
   Mariner stockholders have the right to elect to receive all cash ($26.00 per share), all Apache
   common stock (0.24347 of a share of Apache common stock) or the Mixed Consideration, subject to
   proration procedures as provided in the Merger Agreement.
   &lt;/div&gt;
   &lt;div align="left" style="font-size: 10pt; margin-top: 6pt"&gt;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;Upon completion of the Merger, each outstanding option to purchase Mariner common stock will
   be converted into a fully vested option to purchase 0.24347 of a share of Apache common stock.
   &lt;/div&gt;
   &lt;div align="left" style="font-size: 10pt; margin-top: 6pt"&gt;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;In addition, each outstanding share of Mariner restricted stock (other than restricted stock
   granted pursuant to Mariner&amp;#8217;s 2008 Long-Term Performance-Based Restricted Stock Program) that is
   not subject to an unsatisfied price or other condition and that has not lapsed will vest and each
   holder will have the opportunity to elect the form of consideration as described above. Forty
   percent of the outstanding shares of Mariner restricted stock granted pursuant to its 2008
   Long-Term Performance-Based Restricted Stock Program will vest and each holder will have the
   opportunity to elect the form of consideration as described above, and the remaining portion of
   such shares of Mariner restricted stock will be cancelled.
   &lt;/div&gt;
   &lt;div align="left" style="font-size: 10pt; margin-top: 6pt"&gt;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;The Merger Agreement has been approved by the boards of directors of Apache, Mariner, and
   Merger Sub. The completion of the Merger is subject to certain conditions, including: (i)&amp;#160;the
   adoption of the Merger Agreement by the stockholders of Mariner; (ii)&amp;#160;subject to certain
   materiality exceptions, the accuracy of the representations and warranties made by Apache and
   Mariner; (iii)&amp;#160;the effectiveness of a registration statement on Form S-4 that will be filed by
   Apache for the issuance of its common stock in the Merger, and the approval of the listing of these
   shares on the New York Stock Exchange; (iv)&amp;#160;the termination or expiration of the applicable waiting
   period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended; (v)&amp;#160;the delivery
   of customary opinions from counsel to Apache and Mariner that the Merger will be treated as a
   tax-free reorganization for U.S. federal income tax purposes; (vi)&amp;#160;compliance by Apache and Mariner
   with their respective obligations under the Merger Agreement; and (vii)&amp;#160;the absence of legal
   impediments prohibiting the Merger.
   &lt;/div&gt;
   &lt;div align="left" style="font-size: 10pt; margin-top: 6pt"&gt;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;The Merger Agreement also contains customary representations and warranties that the parties
   have made to each other as of specific dates. Apache and Mariner also have each agreed to certain
   covenants in the Merger Agreement. Among other covenants, Mariner has agreed, subject to certain
   exceptions, not to initiate, solicit, negotiate, provide information in furtherance of, approve,
   recommend or enter into an Acquisition Proposal (as defined in the Merger Agreement).
   &lt;/div&gt;
   &lt;div align="left" style="font-size: 10pt; margin-top: 6pt"&gt;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;The Merger Agreement contains certain termination rights for both Apache and Mariner,
   including if the Merger is not completed by January&amp;#160;31, 2011. In the event of a termination of the
   Merger Agreement under certain circumstances, Mariner may be required to pay to Apache a
   termination fee of $67.0&amp;#160;million. In certain circumstances involving the termination of the Merger
   Agreement, one of Apache or Mariner will be obligated to reimburse the other&amp;#8217;s expenses incurred in
   connection with the transactions contemplated by the Merger Agreement in an aggregate amount not to
   exceed $7.5&amp;#160;million. Any reimbursement of expenses by Mariner to Apache will reduce the amount of
   any termination fee paid by Mariner to Apache.
   &lt;/div&gt;
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   &lt;div align="left" style="font-size: 10pt; margin-top: 6pt"&gt;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;In connection with the Merger Agreement, Mariner and Continental Stock Transfer &amp;#038; Trust
   Company (the &amp;#8220;Rights Agent&amp;#8221;), entered into an Amendment to Rights Agreement, dated as of April&amp;#160;14,
   2010 (the &amp;#8220;Amendment&amp;#8221;), to the Rights Agreement dated as of October&amp;#160;12, 2008 (the &amp;#8220;Rights
   Agreement&amp;#8221;), between Mariner and the Rights Agent, in connection with the execution of the Merger
   Agreement. Undefined capitalized terms used in this paragraph have the meaning ascribed to them in
   the Rights Agreement. The Amendment provides that none of (i)&amp;#160;the announcement of the Merger, (ii)
   the execution and delivery of the Merger Agreement, (iii)&amp;#160;the conversion of shares of Mariner
   common stock into the right to receive the Merger Consideration (as defined in the Merger
   Agreement) or (iv)&amp;#160;the consummation of the Merger or any other transaction contemplated by the
   Merger Agreement will cause (1)&amp;#160;Apache, Merger Sub or any of their Affiliates or Associates to
   become an Acquiring Person, or (2)&amp;#160;the occurrence of a Flip-In Event, a Flip-Over Event, a
   Distribution Date or a Stock Acquisition Date under the Rights Agreement.
   &lt;/div&gt;
   &lt;div align="left" style="font-size: 10pt; margin-top: 6pt"&gt;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;Subsequent to the announcement of the merger with Apache, two stockholder lawsuits styled as
   class actions were commenced on behalf of Mariner stockholders challenging the merger. &lt;i&gt;City of
   Livonia Employees&amp;#8217; Retirement System v. Mariner Energy, Inc., et al&lt;/i&gt;, Cause No.&amp;#160;2010-24355, was
   filed in the 334th Judicial District Court of Harris County, Texas against Mariner and its
   directors. Plaintiff alleges that the Mariner directors breached their fiduciary duties by agreeing
   to sell the company through an unfair process and at an unfair price, and that Mariner aided and
   abetted those breaches of fiduciary duties. Plaintiff seeks to enjoin the transaction and to be
   awarded attorney&amp;#8217;s fees. &lt;i&gt;Southeastern Pennsylvania Transportation Authority v. Scott D. Josey, et
   al&lt;/i&gt;, cause No.&amp;#160;5427-VCP, was filed in the Court of Chancery of the State of Delaware against
   Mariner, its directors, certain Mariner officers, Apache and Merger Sub. Plaintiff alleges that the
   Mariner directors breached their fiduciary duties by agreeing to sell the company through an unfair
   process and at an unfair price, and by agreeing to the vesting of certain restricted stock held by
   Mariner management. Plaintiff also alleges that Apache and Merger Sub aided and abetted in those
   breaches of fiduciary duties. Plaintiff seeks to enjoin the merger and to be awarded attorney&amp;#8217;s
   fees.
   &lt;/div&gt;
   &lt;div align="left" style="font-size: 10pt; margin-top: 6pt"&gt;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;On August&amp;#160;1, 2010, the parties to the Delaware action entered into a memorandum of
   understanding, which, when reduced to a settlement agreement, is intended to be a final resolution
   of that action. Also on August&amp;#160;1, 2010, the parties to the Texas action agreed to be bound by the
   memorandum of understanding with respect to that action. In connection with the settlement, and in
   exchange for the releases described below, Apache and Mariner agreed to, and on August&amp;#160;2, 2010
   Apache, Mariner and Merger Sub did, amend the Merger Agreement to eliminate the termination fee in
   the event that Mariner terminates the Merger Agreement in order to enter into a &amp;#8220;superior proposal&amp;#8221;
   with another party and to make certain additional disclosures in the proxy statement/prospectus for
   the transaction filed with the Securities and Exchange Commission. Additionally, in the event that
   any proceedings regarding appraisal rights under Section&amp;#160;262 of the Delaware General Corporation
   Law are commenced following the merger, Apache and Mariner have waived and will not present any
   argument that shares of Mariner restricted stock granted pursuant to Mariner&amp;#8217;s 2008 Long-Term
   Performance-Based Restricted Stock Program will be counted in determining the total number of
   Mariner shares outstanding in such proceeding.
   &lt;/div&gt;
   &lt;div align="left" style="font-size: 10pt; margin-top: 6pt"&gt;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;Subject to the completion of agreed-upon confirmatory discovery, the parties will negotiate in
   good faith to execute a settlement agreement to present to the Court of Chancery of the State of
   Delaware. Pursuant to the settlement, the Delaware action will be dismissed with prejudice on the
   merits, the plaintiffs in the Texas action will voluntarily dismiss that action with prejudice, and
   all defendants will be released from any and all claims relating to, among other things, the
   merger, the Merger Agreement and any disclosures made in connection therewith. The settlement is
   subject to customary conditions, including consummation of the merger, completion of certain
   confirmatory discovery, class certification, and final approval by the Court of Chancery of the
   State of Delaware.
   The settlement will not affect the form or amount of the consideration to be
   received by Mariner stockholders in the merger.
   &lt;/div&gt;
   &lt;div align="left" style="font-size: 10pt; margin-top: 6pt"&gt;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;The defendants have denied and continue to deny any wrongdoing or liability with
   respect to all claims, events, and transactions complained of in these actions or that they
   have engaged in any wrongdoing. The defendants entered into the settlement to eliminate the
   uncertainty, burden, risk, expense and distraction of further litigation.
   &lt;/div&gt;
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