EXECUTIVE
      CHANGE IN CONTROL

    SEVERANCE
      AGREEMENT

     

    THIS
      EXECUTIVE CHANGE IN CONTROL SEVERANCE AGREEMENT
      (“Agreement”),
      effective as of December 30th,
      2005
      (the “Effective Date”), by and between Frontier Oil Corporation, a Wyoming
      corporation (the “Company”), and Doug S. Aron (the “Executive”).

     

    WITNESSETH:

     

    WHEREAS,
      the
      parties desire to enter into this Agreement; and

     

    WHEREAS,
      the
      parties agree that on and after the Effective Date and prior to a Change in
      Control (as defined below) the Executive is an “at will” employee of the
      Company;

     

    NOW,
      THEREFORE,
      in
      consideration of the premises and covenants herein contained and other good,
      valuable and binding consideration, the receipt and sufficiency of which are
      hereby acknowledged, the parties agree as follows:

     

    1.  Operation
      of Agreement.

     

    1.01  This
      Agreement is effective as of the Effective Date. Unless terminated earlier
      as
      provided herein, this Agreement shall terminate on the third anniversary of
      the
      Effective Date; provided, however, if a Change in Control (as defined below)
      of
      the Company occurs during the term of this Agreement, the term of this Agreement
      automatically shall terminate on the 18 month anniversary of the effective
      date
      of the Change in Control (the “CiC Date”), regardless of the length of the term
      remaining as of the CiC Date. Notwithstanding any provision of this Agreement
      to
      the contrary, termination of this Agreement shall not alter or impair any rights
      or benefits of the Executive (or his estate or beneficiaries) that have arisen
      under this Agreement on or prior to such termination, including any contingent
      rights under paragraph 1.03.

     

    1.02  For
      the
      purpose of this Agreement, the term “Change in Control” of the Company means the
      occurrence of any one of the following on or after the Effective
      Date:

     

    (a)  the
      consummation of any transaction (including without limitation, any merger,
      consolidation, tender offer, or exchange offer) the result of which is that
      any
      individual, entity, group or “person” (as such term is used in Sections 13(d)(3)
      and 14(d)(2), of the Securities Exchange Act of 1934 (the “Exchange
      Act”)),
      other
      than the Company, a subsidiary or an employee benefit plan of
      either, becomes
      the “beneficial owner” (as such term is defined in Rule 13d-3 and Rule 13d-5
      under the Exchange Act), directly or indirectly, of stock and/or securities
      of
      the Company representing 25% or more of the combined voting power of the
      Company’s then outstanding voting securities,

     

    (b)  a
      change
      in the composition of the Board of Directors of the Company, as a result of
      which fewer than a majority of the non-employee directors are Incumbent
      Directors. “Incumbent Directors” shall mean non-employee directors who either
      (A) are non-employee Directors as of the date the Plan is adopted, or (B) are
      elected, or nominated for election, thereafter to the Board of Directors with
      the affirmative votes of at least a majority of the Incumbent Directors at
      the
      time of such election or nomination, but “Incumbent Director” shall not include
      an individual whose election or nomination is in connection with (i) an actual
      or threatened election contest (as such terms are used in Rule 14a-11 of
      Regulation 14A promulgated under the Securities Exchange Act of 1934) or an
      actual or threatened solicitation of proxies or consents by or on behalf of
      a
      Person other than the Board of Directors or (ii) a plan or agreement to replace
      a majority of the then Incumbent Directors,

     

    (c)  the
      consummation of the sale, lease, transfer, conveyance or other disposition
      (including by merger or consolidation) in one or a series of related
      transactions, of all or substantially all of the assets of the Company and
      its
      subsidiaries, taken as a whole (other
      than to an entity wholly owned, directly or indirectly, by the Company), unless,
      following such transaction all or substantially all of the persons who were
      the
      beneficial owners of the outstanding voting stock and securities of the Company
      immediately prior to such transaction beneficially own, directly or indirectly,
      more than 60% of, respectively, the then outstanding voting stock and securities
      of the entity resulting from such transaction in substantially the same
      proportions as immediately prior to such transaction,
      or

     

    (d)  the
      adoption of a plan relating to the liquidation or dissolution of the
      Company.

     

    1.03  Except
      as
      provided below, this Agreement automatically shall terminate in the event the
      Executive ceases for any reason to be an employee of the Company and its
      affiliates prior to a Change in Control; provided, however, if the Executive’s
      employment is terminated during the six-month period preceding a Change in
      Control that would have occurred during the term of this Agreement but for
      the
      termination of this Agreement upon the Executive’s termination of employment,
      and if his termination would have qualified as a Termination of Employment
      under
      paragraph 7.02(a) or paragraph 7.02(b)(ii) (without regard to the 30/60 day
      periods provided in paragraph 7.02(b)(ii)), then within 30 days of such Change
      in Control the Company shall pay the Executive a lump sum amount equal to 1.5
      (one and one half) times the sum of (i) his annual Base Salary, (ii) the annual
      Target Bonus amount, and (iii) in recognition of the benefits and perquisites
      described in paragraphs 5.02 and 4.03, an amount equal to 30% of his annual
      Base
      Salary. Further, if at the time of his termination of employment the Executive
      held any equity-based compensation awards that were forfeited by the Executive
      upon such termination, the Company shall pay the Executive a lump sum amount
      equal to the sum of the Fair Market Value of the shares subject to such
      forfeited awards less the sum of the exercise prices, if any, of such awards;
      provided, however, with respect to any such forfeited award that was a stock
      option, the Company, in its sole discretion, may, in lieu of a cash payment
      with
      respect to such forfeited stock option, reinstate and fully vest such stock
      option in which event such reinstated stock option shall continue for the
      remainder of its full term notwithstanding the Executive’s earlier termination
      of employment. Solely for the purpose of this paragraph, Fair Market Value
      shall
      mean the reported closing price of the common shares of the Company on the
      date
      of the Change in Control. In addition, any stock options held by the Executive
      on the CiC Date shall remain exercisable for the remainder of their terms as
      if
      the Executive’s employment had not terminated. 

     

    1.04  Nothing
      in this Agreement shall operate or be construed to create any right or duty
      on
      the part of the Company or the Executive to remain in the employment of the
      Company for any period of time prior to the date of a Change in Control, each
      reserving all rights to terminate the “at will” employment relationship of the
      Executive at any time prior to a Change in Control.

     

    2.  Period
      of Employment.

     

    2.01  If
      a
      Change in Control occurs during the term of this Agreement, the Company agrees
      to continue the Executive in its employ for the period set forth in paragraph
      2.02 below (the “Period of Employment”) in the position and with the duties and
      responsibilities set forth in Section 3 below, and upon the other terms and
      conditions hereinafter provided. 

     

    2.02  Subject
      to (i) the provisions of Section 6 below, (ii) the termination of the Executive
      by the Company for Cause or (iii) a termination by the Executive other than
      pursuant to Section 7.02(b), the Period of Employment shall continue for a
      period of eighteen
      months
      from the
      CiC Date.

     

    3.  Position,
      Duties, Responsibilities.

     

    3.01  During
      the Period of Employment, the Executive shall continue to serve as the VP -
      Corporate Finance of the Company and continue to have the duties and
      responsibilities of such position that the Executive possessed immediately
      prior
      to the CiC Date.

     

    3.02  During
      the Period of Employment, the Executive shall also serve and continue to serve,
      if and when elected and reelected, as an officer or director, or both, of any
      affiliate of the Company.

     

    3.03  Throughout
      the Period of Employment, the Executive shall devote his full time and undivided
      attention during normal business hours to the business and affairs of the
      Company, except for reasonable vacations, illness or incapacity; however,
      nothing in this Agreement shall preclude the Executive from (i) devoting
      reasonable periods required for serving as a director or member of a committee
      of any organization that does not involve a conflict of interest with the
      interests of the Company, (ii) engaging in charitable and community activities,
      and (iii) managing his personal investments, provided that such activities
      do
      not materially interfere with the regular performance of his duties and
      responsibilities under this Agreement. The Board of Directors of the Company
      shall give the Executive written notice of any such activities that it believes
      materially interfere with his duties hereunder and provide the Executive with
      a
      reasonable period of time to correct such activities.

     

    3.04  During
      the Period of Employment, the Executive shall be based at the principal offices
      of the Company maintained in Houston, Texas. The Executive shall not be required
      to be absent from the office on travel status or otherwise more than a total
      of
      60 business days in any calendar year nor more than 20 consecutive days at
      any
      one time.

     

    4.  Compensation,
      Compensation Plans, Perquisites.

     

    4.01  During
      the Period of Employment, the Executive shall be:

     

    (a)  paid
      an
      annual base salary at no less than the rate in effect immediately prior to
      the
      CiC Date, with increases (if any) as shall be made from time to time thereafter
      in accordance with the Company’s regular salary administration practices for key
      executives (“Base Salary”); and

     

    (b)  provided
      an annual bonus opportunity in an amount no less than 40% of his Base Salary
      (“Target Bonus”).

     

    Any
      increase in Base Salary or the Target Bonus or other compensation shall in
      no
      way diminish any other obligation of the Company under this
      Agreement.

     

    4.02  During
      the Period of Employment, the Executive shall continue to be eligible to
      participate in the Company’s equity-based compensation plans and all other
      compensation and incentive plans and programs in which the Executive
      participates immediately prior to the CiC Date (or equivalent successor plans
      that may be adopted by the Company), including, without limitation, an annual
      bonus plan, and the Executive shall be provided thereunder with at least the
      same reward opportunities in the aggregate that were provided to the Executive
      immediately prior to the CiC Date, unless there has been a material diminution
      in the Executive’s performance or duties. Nothing in this Agreement (i) shall be
      construed as requiring the Executive to receive during the Period of Employment
      payments or benefits under such equity, compensation and incentive plans or
      programs that are at least equal to those the Executive received thereunder
      immediately prior to the CiC Date, it being the intent of the parties that
      the
      payments and benefits provided thereunder shall be subject to being earned
      by
      the Executive under the then existing criteria for awards under such plans
      and
      programs, which criteria shall be based on substantially the same performance
      standards and criteria used by the Company immediately prior to the CiC Date,
      or
      (ii) shall preclude improvement of any reward opportunities in such plans or
      other plans or programs in accordance with the practice of the
      Company.

     

    4.03  During
      the Period of Employment, the Executive shall be entitled to perquisites,
      including, without limitation, an office, secretarial and clerical staff, and
      to
      fringe benefits, including, without limitation, the payment or reimbursement
      of
      club dues, in each case at least equal to those provided to the Executive
      immediately prior to the CiC Date, as well as to reimbursement, upon proper
      accounting, of reasonable expenses and disbursements incurred by him in the
      course of his duties.

     

    5.  Employee
      Benefit Plans.

     

    5.01  The
      compensation and other matters provided for in Section 4 above are in addition
      to the benefits provided for in this Section 5.

     

    5.02  During
      the Period of Employment, the Executive, his dependents and eligible
      beneficiaries shall be entitled to all coverage, participation, payments and
      benefits, including service credit for benefits, to which officers of the
      Company, their dependents and beneficiaries are entitled under the terms of
      the
      employee benefit plans and practices of the Company in effect immediately prior
      to the CiC Date, including, without limitation, the Company’s qualified and
      nonqualified retirement programs, 401(k) and profit sharing plans, the Frontier
      Oil Corporation Executive Life Insurance Plan, group life insurance plans,
      accidental death and dismemberment insurance, business travel insurance, long
      term disability, medical, dental and health and other welfare benefit plans
      and
      any successor benefit plans and practices of the Company and its affiliates
      for
      which officers, their dependents and beneficiaries are eligible.

     

    5.03  Nothing
      in this Agreement shall preclude the Company during the Period of Employment
      from amending or terminating any perquisites provided to the Executive or any
      of
      its employee benefit plans or practices in which the Executive participates,
      provided that in the event of any such amendment or termination, the Executive
      shall be entitled during the remaining Period of Employment to perquisites
      and
      benefits (and service credit for benefits) in one or more successor plans or
      arrangements that are at least as comparable in the aggregate to those he
      received immediately prior to the CiC Date. 

     

    6.  Effect
      of Death or Disability.

     

    6.01  In
      the
      event of the death of the Executive during the Period of Employment, the legal
      representative of the Executive’s estate shall be entitled to receive a lump sum
      payment equal to the sum of (i) the Executive’s annual Base Salary and annual
      Target Bonus amount and (ii) the Fair Market Value of the shares subject to
      any
      equity-based compensation awards forfeited as a result of the Executive’s death,
      less the exercise price, if any, of such forfeited awards. Such payment shall
      be
      made as soon as reasonably practical following the Executive’s death and will be
      without prejudice to any other payments or benefits, if any, due hereunder
      in
      respect of the Executive’s death or pursuant to any other plans, agreements or
      arrangements with the Company.

     

    6.02  The
      term
“Disability,” as used in this Agreement, means an illness or accident which
      prevents the Executive from performing his duties under this Agreement. In
      the
      event of the Disability of the Executive during the Period of Employment, the
      Executive shall continue to receive the full compensation, benefits and
      perquisites provided for in this Agreement for the period of such Disability
      or
      the balance of the Period of Employment, whichever is less, reduced by any
      other
      payments made to the Executive pursuant to any disability, illness or accident
      plan of the Company or any affiliate.

     

    7.  Termination
      of Employment.

     

    7.01  In
      the
      event of a “Termination of Employment,” as defined in paragraph 7.02 below,
      during the Period of Employment,

     

    (a)  the
      Company shall pay to the Executive (or his dependents, beneficiaries or estate
      as the case may be), within 30 days of his Termination of Employment, a lump
      sum
      amount equal to (1) one and one half times the sum of (i) his annual Base
      Salary, (ii) the annual Target Bonus amount, and (iii) in recognition of the
      benefits and perquisites described in paragraphs 5.02 and 4.03, an amount equal
      to 30% of his annual Base Salary minus
      (2)
      the amount of (i) any Base Salary and Target Bonus amounts that have been paid
      to the Executive for services performed during the Period of Employment and
      (ii)
      30% of his Base Salary multiplied by a fraction, the numerator of which is
      the
      number of days in the Period of Employment that have lapsed and the denominator
      of which is the total number of days in the Period of Employment if it continued
      for its full term,
      

     

    (b)  all
      outstanding stock options and other equity-based compensation awards held by
      the
      Executive at the time of his Termination of Employment (without regard to when
      granted) automatically shall vest in full and remain exercisable for the
      remainder of their terms as if the Executive’s employment had not
      terminated,

     

    (c)  if
      Section 409A of the Internal Revenue Code would subject the Executive to the
      additional 20% tax provided thereunder with respect to any severance amounts
      paid under this Agreement to the Executive within six months of the Executive’s
      Termination of Employment, such payment shall be deferred until the end of
      such
      six-month period or, if earlier, the date such payment may be made without
      being
      subject to such additional tax under Section 409A and for such period until
      paid
      shall bear interest as provided in paragraph 7.01(d), and

     

    (d)  any
      delay
      by the Company in paying any amount due the Executive under this Agreement
      or
      deferral pursuant to paragraph (c) above shall bear interest at the maximum
      nonusurious rate from the date such payment was due (disregarding for this
      purpose any deferral pursuant to paragraph (c) above) until paid.

     

    7.02  “Termination
      of Employment,” for the purpose of this Agreement,
      means:

     

    (a)  a
      termination of the employment of the Executive by the Company and its affiliates
      during the Period of Employment for any reason other than for (i) Cause, as
      defined in paragraph 7.03 below, or (ii) Disability; or

     

    (b)  a
      termination by the Executive of his employment with the Company and its
      affiliates during the Period of Employment upon the occurrence of any of the
      following events:

     

    (i)  the
      failure to elect or reelect the Executive to, or removal of the Executive from,
      the offices set forth in paragraph 3.01 above,

     

    (ii)  a
      significant change in the nature or scope of the authorities, powers, functions
      or duties of the Executive as contemplated by paragraph 3.01 above, or a
      reduction in the compensation under paragraph 4.01(a) or the perquisites or
      benefits provided under this Agreement, and such change and/or reduction is
      not
      remedied within 30 days after receipt by the Company of written notice from
      the
      Executive;
      provided, however, such written notice must be given by the Executive within
      60
      days of the date the Executive knows, or should reasonably have known, of such
      change or reduction and if notice is not given by the Executive within such
      period, he shall be deemed to have waived his rights with respect to such change
      or reduction constituting a basis for his Termination of
      Employment,

     

    (iii)  a
      determination by the Executive made in good faith that as a result of the Change
      in Control of the Company and a change in circumstances thereafter that
      significantly affects his position, he is unable to carry out the authorities,
      powers, functions or duties attached to his position as contemplated by Section
      3 of this Agreement,
      and
      such change in circumstance is not remedied within 30 days after receipt by
      the
      Company of written notice from the Executive,

     

    (iv)  a
      breach
      by the Company of any material
      provision of this Agreement that is not remedied within 30 days after receipt
      by
      the Company of written notice from the Executive, or 

     

    (v)  the
      failure of a successor to assume all duties and obligations of the Company
      under
      this Agreement as provided in paragraph 10.10.

     

    An
      election by the Executive to terminate his employment given under the provisions
      of this paragraph 7.02(b) shall not be deemed a voluntary termination of
      employment by the Executive for the purpose of this Agreement or any plan or
      practice of the Company. 

     

    7.03  For
      purposes of this Agreement, the termination of the Executive’s employment shall
      be deemed to have been for “Cause” only if:

     

    (a)  termination
      of his employment shall have been the result of an act or acts of dishonesty
      on
      the part of the Executive constituting a felony and resulting or intended to
      result directly or indirectly in gain or personal enrichment at the expense
      of
      the Company; or

     

    (b)  there
      has
      been a breach by the Executive during the Period of Employment of the provisions
      of paragraph 3.03 above, relating to the time to be devoted to the affairs
      of
      the Company, or of paragraph 8.01, relating to confidential information, and
      such breach results in demonstrably material injury to the Company and with
      respect to any alleged breach of paragraph 3.03 or of paragraph 8.01 hereof,
      the
      Executive after notice and an opportunity to be heard either shall have failed
      to take all reasonable steps to that end within 30 days from his receipt of
      written notice by the Company pursuant to resolution duly adopted by a majority
      of the members of the Board of Directors of the Company; and provided that
      thereafter

     

    (c)  there
      shall have been delivered to the Executive a certified copy of a resolution
      of
      the Board of Directors of the Company adopted by the affirmative vote of not
      less than three-fourths of the entire membership of the Board of Directors
      called and held for that purpose and at which the Executive was given an
      opportunity to be heard, finding that the Executive was guilty of conduct set
      forth in subparagraphs (a) or (b) above, specifying the particulars thereof
      in
      detail.

     

    Anything
      in this paragraph 7.03 or elsewhere in this Agreement to the contrary
      notwithstanding, the employment of the Executive shall in no event be considered
      to have been terminated by the Company for Cause if termination of his
      employment took place (a) as the result of bad judgment or negligence on the
      part of the Executive, or (b) as the result of an act or omission without the
      intent of gaining therefrom, directly or indirectly, a profit to which the
      Executive was not legally entitled, or (c) because of an act or omission
      believed by the Executive in good faith to have been in or not opposed to the
      interest of the Company, or (d) for any act or omission in respect of which
      a
      determination could properly be made that the Executive met the applicable
      standard of conduct prescribed for indemnification or reimbursement or payment
      of expenses under the Policies of the Company or the laws of the State of
      Wyoming or the directors’ and officers’ liability insurance of the Company, in
      each case as in effect at the time of such act or omission, or (e) as the result
      of an act or omission that occurred or began more than twelve calendar months
      prior to the Executive’s having been given notice of his Termination of
      Employment for such act or omission, unless the commission or commencement
      of
      such act or such omission could not have been reasonably known to a member
      of
      the Board of Directors of the Company (other than the Executive, if he is then
      a
      member of the Board of Directors) in the twelve month period from the date
      of
      the commission or commencement of such act or such omission.

     

    7.04  In
      the
      event that the Executive’s employment shall be terminated by the Company during
      the Period of Employment and such termination is alleged to be for Cause, or
      the
      Executive’s right to terminate his employment under paragraph 7.02(b) above
      shall be questioned by the Company or for any reason, the Executive shall have
      the right, in addition to all other rights and remedies provided by law, at
      his
      election either to seek arbitration in Houston, Harris County, Texas, under
      the
      rules of the American Arbitration Association by serving a notice to arbitrate
      upon the Company or to institute a judicial proceeding in Houston, Harris
      County, Texas, in either case within 90 days after having received written
      notice that his Termination of Employment is subject to question or that the
      Company is withholding or proposes to withhold any payments or provision of
      benefits or within such longer period as may reasonably be necessary for the
      Executive to take action in the event that his illness or incapacity should
      preclude his taking such action within such 90-day period.

     

    7.05  Each
      party hereto hereby irrevocably submits to the exclusive jurisdiction of the
      state and federal courts in Houston, Harris County, Texas, for the purposes
      of
      any proceeding arising out of this Agreement.

     

    8.  Confidential
      Information

     

    8.01  The
      Executive agrees not to disclose, either while in the Company’s employ or at any
      time thereafter, to any person not employed by the Company, or not engaged
      to
      render services to the Company, any confidential information obtained by him
      while in the employ of the Company, including, without limitation, any of the
      Company’s inventions, processes, methods of distribution or customers or trade
      secrets; provided, however, that this provision shall not preclude the Executive
      from use or disclosure of information known generally to the public or of
      information not considered confidential by persons engaged in the business
      conducted by the Company or from disclosure required by law or Court
      order.

     

    8.02  The
      Executive also agrees that upon leaving the Company’s employ he will not take
      with him, without the prior written consent of an officer authorized to act
      in
      the matter by the Board of Directors of the Company, any drawing, blueprint,
      specification or other document of the Company and its affiliates, which is
      of a
      confidential nature relating to the Company and its affiliates, or without
      limitation, relating to its or their methods of distribution, or any description
      of any formulae or secret processes.

     

    9.  Notices

     

    All
      notices, requests, demands and other communications provided for by this
      Agreement shall be deemed to have been duly given if and when mailed in the
      continental United States by registered or certified mail, return receipt
      requested, postage prepaid, or personally delivered or sent by telex or other
      telegraphic means to the party entitled thereto at the address stated below
      or
      to such changed address as the addressee may have given by a similar
      notice:

     

    To
      the
      Company: Frontier
      Oil Corporation

    10000
      Memorial Drive

    Suite
      600

    Houston,
      Texas 77024

    Attn:
      General Counsel

    


    To
      the
      Executive: Doug
      S.
      Aron

    4904
      Maple St.  

    Bellaire,
      TX 77401

     

    


     

    10.  General
      Provisions

     

    10.01  There
      shall be no right of set-off, mitigation or counterclaim in respect of any
      claim, debt or obligation, against any payments to the Executive, his
      dependents, beneficiaries or estate provided for in this Agreement.

     

    10.02  The
      Company and the Executive recognize that each party will have no adequate remedy
      at law for breach by the other of any of the agreements contained herein and,
      in
      the event of any such breach, the Company and the Executive hereby agree and
      consent that the other shall be entitled to a decree of specific performance,
      mandamus or other appropriate remedy to enforce performance of such
      agreements.

     

    10.03  No
      right
      or interest or in any payments shall be assignable by the Executive; provided,
      however, that this provision shall not preclude him from designating one or
      more
      beneficiaries to receive any amount that may be payable after his death and
      shall not preclude the legal representative of his estate from assigning any
      right hereunder to the person or persons entitled thereto under his will or,
      in
      the case of intestacy, to the person or persons entitled thereto under the
      laws
      of intestacy applicable to his estate. The term “beneficiaries” as used in this
      Agreement shall mean a beneficiary or beneficiaries so designated to receive
      any
      such amount or, if no beneficiary has been so designated, the legal
      representative of the Executive’s estate.

     

    10.04  No
      right,
      benefit or interest hereunder, shall be subject to anticipation, alienation,
      sale, assignment, encumbrance, charge, pledge, hypothecation, or set-off in
      respect of any claim, debt or obligation, or to execution, attachment, levy
      or
      similar process, or assignment by operation of law. Any attempt, voluntary
      or
      involuntary, to effect any action specified in the immediately preceding
      sentence shall, to the full extent permitted by law, be null, void and of no
      effect.

     

    10.05  In
      the
      event of the Executive’s death or a judicial determination of his incompetence,
      reference in this Agreement to the Executive shall be deemed, where appropriate,
      to his beneficiary or beneficiaries. This Agreement shall inure to the benefit
      of and be enforceable by Executive’s personal or legal representatives,
      executors, administrators, successors, heirs, distributees, devisees and
      legatees.

     

    10.06  The
      titles to sections in this Agreement are intended solely for convenience and
      no
      provision of this Agreement is to be construed by reference to the title of
      any
      section.

     

    10.07  No
      provision of this Agreement may be amended, modified or waived unless such
      amendment, modification or waiver shall be authorized by the Board of Directors
      of the Company or any authorized committee of the Board of Directors and shall
      be agreed to in writing, signed by the Executive and by an officer of the
      Company thereunto duly authorized.

     

    10.08  
      Except
      as otherwise specifically provided in this Agreement, no waiver by either party
      hereto of any breach by the other party hereto of any condition or provision
      of
      this Agreement to be performed by such other party shall be deemed a waiver
      of a
      subsequent breach of such condition or provision or a waiver of a similar or
      dissimilar provision or condition at the same or at any prior or subsequent
      time.

     

    10.09  In
      the
      event that any provision or portion of this Agreement shall be determined to
      be
      invalid or unenforceable for any reason, the remaining provisions and portions
      of this Agreement shall be unaffected thereby and shall remain in full force
      and
      effect to the fullest extent permitted by law.

     

    10.10  Except
      in
      the case of a merger involving the Company with respect to which under
      applicable law the surviving corporation of such merger will be obligated under
      this Agreement in the same manner and to the same extent as the Company would
      have been required if no such merger had taken place, the Company will require
      any successor, by purchase or otherwise, to all or substantially all of the
      business and/or assets of the Company, to execute an agreement whereby such
      successor expressly assumes and agrees to perform this Agreement in the same
      manner and to the same extent as the Company would have been required if no
      such
      succession had taken place and expressly agrees that the Executive may enforce
      this Agreement against such successor. Failure of the Company to obtain any
      such
      required agreement and to deliver such agreement to the Executive prior to
      the
      effectiveness of any such succession shall be a material breach of this
      Agreement and shall entitle the Executive to payment from the Company in the
      same amount and on the same terms as the Executive would be entitled hereunder
      if the Executive had incurred a Termination of Employment on the effective
      date
      of such succession (without regard to whether the employment of the Executive
      terminates on such effective date or has terminated after such effective date).
      However, in no event shall the Executive be entitled to payment under both
      paragraph 7.01 and this paragraph 10.10. As used in this Agreement, “Company”
shall mean the Company as hereinbefore defined and any successor to its business
      and/or assets as aforesaid that executes and delivers the agreement provided
      for
      in this paragraph 10.10 or which otherwise becomes bound by all the terms and
      provisions of this Agreement by operation of law.

     

    10.11  This
      Agreement shall be governed by and construed in accordance with the laws of
      the
      State of Texas.

     

    10.12  To
      the
      extent that any payment made or benefit provided to the Executive pursuant
      to
      the terms of this Agreement or otherwise results in the Executive being subject
      to any income, excise, or other tax at a rate above the rate ordinarily
      applicable to wages and salaries paid in the ordinary course of business
      (“Penalty Tax”), whether as a result of the provisions of Sections 280G, 4999 or
      409A of the Internal Revenue Code of 1986, as amended, or any similar or
      analogous provisions of the Internal Revenue Code or any other statute, whether
      adopted subsequent to the date hereof or otherwise, then the amount due the
      Executive under this Agreement shall be increased by an amount (the “Additional
      Amount”) such that the net amount received by the Executive after paying any
      applicable Penalty Tax (including any interest or penalties thereon) and any
      federal, state or other taxes on such Additional Amount, shall be equal to
      the
      amount that the Executive would have received if such Penalty Tax were not
      applicable. Such Additional Amount shall be paid to the Executive at such time
      or times that the Penalty Tax is due.

     

    10.13  To
      the
      extent the Executive prevails in whole or in part in any matter contesting
      the
      validity or enforceability of this Agreement or the amount of benefit claimed
      by
      the Executive hereunder, the Company shall pay all legal fees and expenses
      that
      the Executive incurs as a result of or in connection with such matter. The
      Executive shall not be required to mitigate the amount of any payment provided
      for in this Agreement by seeking other employment or otherwise and amounts
      received from other employment or otherwise by the Executive shall not be
      recoupable by the Company against the amounts paid or payable to the Executive
      pursuant to the terms of this Agreement.

     

    Nothing
      in this Agreement shall limit or otherwise adversely effect such rights as
      the
      Executive may have under the terms of any equity award, employee benefit plan,
      incentive compensation arrangement or other agreement with the Company or any
      of
      its affiliates.

    10.14  The
      Company shall withhold from all payments and benefits provided under this
      Agreement all taxes required to be withheld by the Company by applicable
      law.

     

    IN
      WITNESS WHEREOF,
      the
      parties hereto have executed this Agreement effective for all purposes as of
      the
      Effective Date.

     

    FRONTIER
      OIL CORPORATION

     

    By:
           

     

    Name:
           

     

    Title:
            

     

    


    


    EXECUTIVE

    


     

    Doug
      S.
      Aron