Document:

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                                                                   EXHIBIT 10.25

                              EMPLOYMENT AGREEMENT

     EMPLOYMENT AGREEMENT (the "Agreement") dated March 1, 2000 by and between
Clark Refining & Marketing, Inc. (the "Company") and Jeffry N. Quinn (the
"Executive").

     WHEREAS, the Company considers it essential to its best interests and the
best interests of its stockholders to foster the employment of Executive by the
Company during the term of this Agreement and Executive is willing to accept
Executive's employment on the terms hereinafter set forth in this Agreement;

     NOW, THEREFORE, in consideration of the premises and mutual covenants
herein and for other good and valuable consideration, the parties agree as
follows:

1.   Term of Employment; Executive Representation.
     --------------------------------------------

     a. Employment Term.  Subject to the provisions of Section 8 of this
        ---------------
     Agreement, Executive shall be employed by the Company for the three-year
     period commencing on March 1, 2000 and ending on February 28, 2003 (the
     "Employment Term") on the terms and subject to the conditions set forth in
     this Agreement.  Notwithstanding the preceding sentence, commencing March
     1, 2003, and on each anniversary thereof thereafter (each anniversary, an
     "Extension Date"), the Employment Term shall be automatically extended for
     an additional one-year period, unless either party provides the other party
     hereto with 60 days' written notice prior to the next Extension Date that
     the Employment Term shall not be so extended.  For the avoidance of doubt,
     the term "Employment Term" shall include any extension that becomes
     applicable pursuant to the preceding sentence.

     b. Executive Representation.  Executive hereby represents to the Company
        ------------------------
     that the execution and delivery of this Agreement by Executive and the
     Company and the performance by Executive of the Executive's duties
     hereunder shall not constitute a breach of, or otherwise contravene, the
     terms of any employment agreement or other agreement or policy to which
     Executive is a party or otherwise bound.

2.   Position.
     --------

     a.  While employed hereunder, Executive shall serve as the Company's
     Executive Vice-President-Legal, Human Resources, and Public Affairs and as
     an Executive Vice-President of Clark Refining Holdings, Inc. and Clark USA,
     Inc.  Executive shall also serve as the Company's General Counsel, or such
     other title as shall denote his status as the chief legal officer of the
     Company.  However, nothing contained herein shall in any way restrict the
     ability of the Company to assign Executive, with his consent, to other
     positions of equivalent status within the Company. In such positions,
     Executive shall have such duties and authority as shall be determined from
     time to time by the Board of Directors of the Company (the "Board"), and
     the Executive shall report directly to the Chief Executive Officer of the
     Company.  If requested, the Executive shall also serve as a member of the
     Board or the boards of any affiliates of the Company without additional
     compensation.
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                                                                               2

     b.  While employed hereunder, Executive will devote Executive's full
     business time and best efforts to the performance of Executive's duties
     hereunder and will not engage in any other business, profession or
     occupation for compensation or otherwise which would conflict with the
     rendition of such services either directly or indirectly; provided that
                                                               --------
     nothing herein shall preclude Executive, subject to the prior approval of
     the Chief Executive Officer, from accepting appointment to the board of
     directors or trustees of any business corporation or any charitable
     organization, provided in each case, and in the aggregate, that such
     activities do not interfere with the performance of Executive's duties
     hereunder or conflict with Section 9.  Any compensation earned by Executive
     for serving in such director or trustee capacity shall be the sole and
     exclusive property of Executive.

3.   Base Salary.   While employed hereunder, the Company shall pay Executive a
     -----------
base salary (the "Base Salary") at the annual rate of $282,500, payable in
regular installments in accordance with the Company's usual payment practices.
Executive shall be entitled to such increases in Executive's Base Salary, if
any, as may be determined from time to time in the sole discretion of the Board,
and any such increased Base Salary shall be deemed to be Executive's "Base
Salary" for purposes of this Agreement.

4.   Bonuses.
     -------

     a.   Signing Bonus.  As consideration for Executive's entering into this
          -------------
     Agreement, the Company shall pay Executive a one-time signing bonus of
     $125,000, payable as soon as practicable after the date hereof.

     b.   Annual Bonus.  With respect to each calendar year while employed
          ------------
     hereunder, Executive shall be eligible to earn an annual bonus award
     pursuant to the Company's annual incentive plan (the "Annual Incentive
     Plan") in an amount to be determined at the sole discretion of the Board in
     consultation with the Chief Executive Officer. Executive's Annual Bonus
     Opportunity (as defined in the Annual Incentive Plan) shall be 150% of Base
     Salary and his Annual Target Bonus (as defined in the Annual Incentive
     Plan) shall be 100% of Base Salary. However, Executive's Annual Bonus
     Opportunity and Annual Target Bonus shall be subject to change based upon
     modifications made from time to time to the Annual Incentive Plan by the
     Company's management team, which team shall include the Executive,
     provided, however, that in any such modification of the Annual Incentive
     Plan Executive's Annual Bonus Opportunity and Annual Target Bonus shall be
     no less than that of other similarly situated officers of the Company,
     including any Executive Vice President thereof.  Notwithstanding the
     foregoing, Executive shall be entitled to an annual bonus of at least
     $100,000 in respect of calendar year 2000.

5.   Equity Arrangements.  Executive shall be granted an option to purchase
     -------------------
120,000 shares of the common stock of Clark Refining Holdings Inc. (the "Common
Stock") pursuant to the terms of the Clark Refining Holdings Inc. 1999 Stock
Incentive Plan (the "Stock Incentive Plan").  The option shall have a per share
exercise price of $9.90.

     The options for 60,000 shares shall vest ratably over the four years
following the date hereof (1/4 per year), and the options for the remaining
60,000 shares shall vest on the seventh
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                                                                               3

anniversary of the grant date, or upon the achievement of the share prices set
forth below for the Common Stock: (i) following an initial public offering, as
an average closing price for any 180 day consecutive period, or (ii) in a Change
in Control:

     Per Share Price                            % Vested
   ------------------                         ------------
     below    $12.00                                 0%
     $12.00 - $14.99                                10%
     $15.00 - $17.99                                20%
     $18.00 - $19.99                                30%
     $20.00 - $24.99                                50%
     $25.00 - $29.99                                75%
     above    $29.99                               100%

     The specific terms of such grant shall be set forth in a separate option
agreement, and shall be subject to the terms of the Stock Incentive Plan.

6.   Employee Benefits.
     -----------------

     a.   Welfare and Pension Benefits.  The Company shall provide Executive
          ----------------------------
     during the term of his employment hereunder with coverage under all
     employee pension and welfare benefit programs, plans and practices in
     accordance with the terms thereof, which the Company generally makes
     available to its senior executives; provided, however, that the Company
                                         --------  -------
     shall reimburse Executive for the cost of COBRA continuation coverage
     (elected by Executive under his prior employer's group health plan) during
     the first 30 days of the Employment Term (after which time Executive will
     be eligible for coverage under the Company's medical plan pursuant to this
     Section 6(a)).

     b.   Vacation and Other Perquisites.  Executive shall also be entitled to
          ------------------------------
     such number of paid vacation and sick leave days in each calendar year as
     established under the Company's policies as in effect from time to time,
     which shall be taken at such times as are consistent with Executive's
     responsibilities hereunder. In addition, the Company shall reimburse
     Executive for the reasonable cost of financial, estate and tax preparation
     and planning services listed on Exhibit A incurred by Executive during the
     calendar year 2000, upon presentation by Executive from time to time of
     appropriately itemized accounts of such expenditures.  Such accounts shall
     be subject to approval by the Chief Executive Officer.

7.   Business Expenses.   Executive is authorized to incur reasonable expenses
     -----------------
in carrying out his duties and responsibilities under this Agreement, including,
without limitation, expenses for travel and similar items related to such duties
and responsibilities.  The Company will reimburse Executive for all such
expenses upon presentation by Executive from time to time of appropriately
itemized and approved (consistent with the Company's policy) accounts of such
expenditures.
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8.   Termination.  The Executive's employment hereunder may be terminated by
     -----------
either party at any time and for any reason; provided that Executive will be
                                             --------
required to give the Company at least 60 days advance written notice of any
resignation of Executive's employment.  Notwithstanding any other provision of
this Agreement, the provisions of this Section 8 shall exclusively govern
Executive's rights upon termination of employment with the Company and its
affiliates.  Upon termination of Executive's employment for any reason,
Executive agrees to resign, as of the date of such termination, from the Board
and the board of directors of any of the Company's affiliates.

     a.   By the Company For Cause or by Executive Resignation Without Good
          -----------------------------------------------------------------
Reason.
------

          (i) Executive's employment hereunder may be terminated by the Company
          for Cause (as defined below) at any time or, upon 60 days prior
          written notice, by Executive without Good Reason (as defined below).

          (ii) For purposes of this Agreement, "Cause" shall  mean (A)
          Executive's continued failure to substantially perform Executive's
          duties hereunder (other than as a result of total or partial
          incapacity due to physical or mental illness) for a period of 10 days
          following written notice by the Company to Executive of such failure,
          (B) dishonesty in the performance of Executive's duties hereunder, (C)
          an act or acts on Executive's part constituting (x) a felony under the
          laws of Missouri or (y) a misdemeanor involving moral turpitude, (D)
          Executive's willful malfeasance or willful misconduct in connection
          with Executive's duties hereunder or any act or omission which is
          materially injurious to the financial condition or business reputation
          of the Company or any of its subsidiaries or affiliates, (E)
          Executive's breach of the restrictive covenants set forth in Section 9
          hereof or (F) Executive's failure to substantially perform Executive's
          duties hereunder (other than as a result of total or partial
          incapacity due to physical or mental illness) at the Company's
          location in the St. Louis, Missouri metropolitan area, except as
          otherwise required by the Company.

          (iii)  If Executive's employment is terminated by the Company for
          Cause or by Executive without Good Reason, Executive shall be entitled
          to receive:

               (A) the Base Salary through the date of termination;

               (B) any annual bonus earned but unpaid as of the date of
               termination for any previously completed calendar year;

               (C) reimbursement for any unreimbursed business expenses properly
               incurred by Executive in accordance with Company policy prior to
               the date of Executive's termination; and

               (D) such employee benefits, if any, as to which Executive may be
               entitled under the employee benefit plans of the Company (the
               amounts

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               described in clauses (A) through (D) hereof being referred to as
               the "Accrued Rights").

          Following such termination of Executive's employment by the Company
     for Cause or by Executive without Good Reason, except as set forth in this
     Section 8(a),  Executive shall have no further rights to any compensation
     or any other benefits under this Agreement.

     b.   Disability or Death.
          -------------------

          (i) Executive's employment hereunder shall terminate upon Executive's
          death or if Executive becomes physically or mentally incapacitated, as
          determined pursuant to the Company's long-term disability program as
          may be in effect from time to time (the "LTD Program"), and is
          therefore unable, for a period of time as determined under the LTD
          Program, to perform Executive's duties (such incapacity is hereinafter
          referred to as "Disability").  Any question as to the existence of the
          Disability of Executive as to which Executive and the Company cannot
          agree shall be determined in writing by a qualified independent
          physician mutually acceptable to Executive and the Company.  If
          Executive and the Company cannot agree as to a qualified independent
          physician, each shall appoint such a physician and those two
          physicians shall select a third who shall make such determination in
          writing.  The determination of Disability made in writing to the
          Company and Executive shall be final and conclusive for all purposes
          of the Agreement.

          (ii) Upon termination of Executive's employment hereunder for either
          Disability or death, Executive or Executive's estate (as the case may
          be) shall be entitled to receive:

               (A)  the Accrued Rights; and

               (B) a pro rata portion of Executive's annual target bonus based
               upon the percentage of the calendar year that shall have elapsed
               through the date of termination of the Executive's employment,
               payable when such bonus would have otherwise been payable had
               Executive's employment not terminated.

          Following Executive's termination of employment due to death or
     Disability, except as set forth in this Section 8(b), Executive shall have
     no further rights to any compensation or any other benefits under this
     Agreement.
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                                                                               6

     c.   By the Company Without Cause, Expiration of Employment Term, or
          ---------------------------------------------------------------
Resignation by Executive for Good Reason.
----------------------------------------

          (i) The Executive's employment hereunder may be terminated by the
          Company without Cause, by the Company's election not to extend the
          Employment Term, or, upon 60 days prior written notice, by Executive's
          resignation for Good Reason.

          (ii) In the event that the Company elects not to extend the Employment
          Term pursuant to Section 1, unless Executive's employment is earlier
          terminated pursuant to paragraphs (a), (b) or (c) of this Section 8,
          Executive's termination of employment hereunder (whether or not
          Executive continues as an employee of the Company thereafter) shall be
          deemed to occur on the close of business on the day immediately
          preceding the next scheduled Extension Date.

          (iii)  For purposes of this Agreement, "Good Reason" shall mean: (A) a
          reduction in Executive's Base Salary or annual bonus opportunity or
          target bonus (other than any general salary reduction affecting at
          least the majority of salaried employees or annual incentive plan
          changes affecting all similarly situated officers of the Company,
          including any Executive Vice President, and provided that the
          establishment of reasonable performance targets by the Board will not
          constitute a reduction of annual bonus opportunity or target bonus),
          (B) a substantial diminution of Executive's duties and
          responsibilities, or (C) a transfer of Executive's primary workplace
          by more than thirty-five (35) miles from the Executive's workplace
          immediately prior to such transfer.

               Notwithstanding the foregoing, none of the events described in
          clauses  (A), (B) or (C) of this Section 8(c)(ii) shall constitute
          Good Reason unless Executive shall have notified the Company in
                      ------
          writing describing the events which constitute Good Reason and then
          only if the Company shall have failed to cure such event within thirty
          (30) days after the Company's receipt of such written notice.
          However, any termination of Executive's employment by the Company
          after delivery by the Executive to the Company of such notice shall be
          deemed to be a termination without Cause if Good Reason did exist at
          the time such notice was given by Executive.

          (iv) If Executive's employment is terminated by the Company without
          Cause (other than by reason of death or Disability), as a result of
          the Company's nonrenewal of the Employment Term pursuant to Section 1
          hereof, or by Executive's resignation for Good Reason, Executive shall
          be entitled to receive:

               (A)  the Accrued Rights; and

               (B) subject to Executive's continued compliance with the
               provisions of Section 9, an amount equal to two (the "Severance
               Multiplier") times the sum of the (1) then Base Salary and (2)
               then annual target bonus, payable
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                                                                               7

               in accordance with normal payroll practices of the Company in
               substantially equal installments over the 24 month period
               following termination of employment; provided that the aggregate
                                                    --------
               amount described in this clause (B) shall be reduced by the
               present value of any other cash severance or termination benefits
               payable to Executive under any other plans, programs or
               arrangements of the Company or its affiliates.

                    Notwithstanding the foregoing, in the event Executive's
               employment is terminated under this Section 8(c) at any time
               following a Change of Control (defined below), the Severance
               Multiplier shall be increased from two to three, and any
               severance amounts payable pursuant to Section 8(c)(iv)(B) shall
               be payable in the form of a single, lump sum cash payment within
               10 days following termination of employment.

               (C) The Company, at its expense, shall provide the Executive with
               the reasonable job relocation counseling services of a firm
               chosen from time to time by the Executive, for a period not to
               exceed 18 months after the Date of Termination.

               (D) The Company shall maintain in full force and effect, for the
               Executive's continued benefit, until the earlier of (1) one year
               after the date of the termination of Executive's employment or
               (2) the Executive's commencement of full time employment with a
               new employer, all life insurance, medical, dental, health and
               accident and disability plans, programs or arrangements in which
               the Executive was entitled to participate immediately prior to
               the termination of Executive's employment at a cost to the
               Executive no greater than the Executive paid while employed by
               the Company, provided that the Executive's continued
               participation is possible under the general terms and provisions
               of such plans and programs.  In the event that the Executive's
               participation is barred, the Company shall arrange to provide the
               Executive, at the Company's expense, with benefits substantially
               similar to those which the Executive is entitled to receive under
               such plans, programs or arrangements, or pay cash in an amount
               after tax sufficient to enable the Executive to purchase
               substantially similar coverage for a one year period on an
               individual basis, at a cost to the Executive no greater than the
               Executive paid while employed.  In the case of the Executive's
               commencement of full time employment with a new employer within
               the one year period, the Company agrees to make up any
               differential in benefits between what the Executive would have
               received from the Company in the one year period and what the
               Executive receives from his new employer, so that the Executive
               is ensured of receiving the same benefits which he would have
               been entitled to receive from the Company had his employment with
               the Company continued for the one year period
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                                                                               8

               at a cost to the Executive no greater than the Executive paid
               while employed.

          Following Executive's termination of employment by the Company without
     Cause (other than by reason of Executive's death or Disability), as a
     result of the Company's nonrenewal of the Employment Term pursuant to
     Section 1 hereof, or by Executive's resignation for Good Reason, except as
     set forth in this Section 8(c), Executive shall have no further rights to
     any compensation or any other benefits under this Agreement.

     d. Notice of Termination.  Any purported termination of employment by the
        ---------------------
     Company or by Executive (other than due to Executive's death) shall be
     communicated by written Notice of Termination to the other party hereto in
     accordance with Section 11(h) hereof.  For purposes of this Agreement, a
     "Notice of Termination" shall mean a notice which shall indicate the
     specific termination provision in this Agreement relied upon and shall set
     forth in reasonable detail the facts and circumstances claimed to provide a
     basis for termination of employment under the provision so indicated.

     e.  Definition of Change of Control.  For purposes hereof, "Change of
         -------------------------------
     Control" shall mean any transaction, the result of which is that any Person
     (an "Acquiring Person") other than (i) Blackstone (defined below) or (ii)
     any Person, a majority of whose voting equity is owned by Blackstone,
     becomes the beneficial owner, directly or indirectly, of shares of stock of
     the Company or Clark US, Inc. entitling such Acquiring Person to exercise
     50% or more of the total voting power of all classes of stock of the
     Company or Clark USA, Inc., as the case may be, entitled to vote in
     elections of directors.  For purposes hereof, "Blackstone" shall mean,
     collectively, The Blackstone Group, Blackstone Capital Partners III
     Merchant Banking Fund L.P., and their affiliates (other than the Company
     and its subsidiaries) and "Person" shall mean a "person" as such term is
     used for purposes of Section 13(d) or 14(d) of the Securities Exchange Act
     of 1934, as amended.

     f.  (i) In the event it shall be determined that any payment, benefit or
         distribution (or combination thereof) by the Company, or by any other
         member of the same affiliated group with the Company (as determined
         under Code Section 280G(d)(5)) for the benefit of the Executive
         (whether paid or payable or distributed or distributable pursuant to
         the terms of this Agreement, or otherwise) (a "Payment") would be
         subject to the excise tax imposed by Section 4999 of the Internal
         Revenue Code of 1986, as amended from time to time (the "Code"), or any
         interest or penalties are incurred by the Executive with respect to
         such excise tax (other than interest or penalties incurred as a result
         of the failure of the Executive to file any tax return, or pay any tax
         (except any such failure to pay tax in accordance with the terms
         hereof), required by applicable law or to be filed or paid by the
         Executive) (such tax together with any such interest and penalties,
         hereinafter collectively referred to as the "Excise Tax"), the
         Executive shall be entitled to receive an additional payment (a "Gross-
         Up Payment") in an amount such that after payment by the Executive of
         taxes (including payroll taxes and any interest or penalties imposed
         with respect to such taxes, other than interest or penalties imposed as
         a result of the failure of the Executive to file any tax return
<PAGE>

                                                                               9

          or pay any tax (except any such failure to pay tax in accordance with
          the terms hereof), required by applicable law to be filed or paid by
          the Executive), including, without limitation, any income taxes (and
          any interest and penalties imposed with respect thereto, other than
          interest or penalties imposed as a result of the failure of the
          Executive to file any tax return or pay any tax (except any such
          failure to pay tax in accordance with the terms hereof), required by
          applicable law to be filed or paid by the Executive) and the Excise
          Tax imposed upon the Gross-Up Payment, the Executive retains an amount
          of the Gross-Up Payment equal to the Excise Tax imposed upon the
          Payments.

          (ii) Subject to the provisions of subsection 8(g)(iii), all
          determinations required to be made under this subsection 8(g),
          including whether and when a Gross-Up Payment is required and the
          amount of such Gross-Up Payment and the assumptions to be utilized in
          arriving at such determination, shall be made by Deloitte & Touche LLP
          or, if Deloitte & Touche LLP is unable or unwilling to serve, then
          such nationally recognized accounting firm as the Company shall select
          (Deloitte & Touche LLP or such other accounting firm being the
          "Accounting Firm" ), which shall provide detailed supporting
          calculations both to the Company and the Executive within fifteen (15)
          business days of the receipt of notice from the Executive that there
          has been a Payment, or such earlier time as is requested by the
          Company. All fees and expenses of the Accounting Firm shall be borne
          solely by the Company. Any Gross-Up Payment, as determined pursuant to
          this Section 8(g), shall be paid by the Company to the Executive
          within five (5) days after the receipt of the Accounting Firm's
          determination. If the Accounting Firm determines that no Excise Tax is
          payable by the Executive, it shall so indicate to the Executive in
          writing. Any determination by the Accounting Firm shall be binding
          upon the Company and the Executive. As a result of the uncertainty in
          the application of Section 4999 of the Code at the time of the initial
          determination by the Accounting Firm hereunder, it is possible that
          Gross-Up Payments which will not have been made by the Company should
          have been made ("Underpayment"), consistent with the calculations
          required to be made hereunder. In the event that the Corporation
          exhausts its remedies pursuant to subsection 8(g)(iii) and the
          Executive thereafter is required to make a payment of any Excise Tax,
          the Accounting Firm shall determine the amount of the Underpayment
          that has occurred and any such Underpayment shall be promptly paid by
          the Corporation to or for the benefit of the Executive.

          (iii)  The Executive shall notify the Company in writing of any claim
          by the Internal Revenue Service that, if successful, would require the
          payment by the Company of the Gross-Up Payment. Such notification
          shall be given as soon as practicable but no later than ten (10)
          business days after the Executive is informed in writing of such claim
          and shall apprize the Company of the nature of such claim and the date
          on which such claim is requested to be paid. The Executive shall not
          pay such claim prior to the expiration of the thirty (30) day period
          following the date on which it gives such notice to the Company (or
          such shorter period ending on the date that any payment of taxes with
          respect to such claim is
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                                                                              10

          due). If the Company notifies the Executive in writing prior to the
          expiration of such period that it desires to contest such claim, the
          Executive shall:

               (A) give the Company any information requested by the Company
               relating to such claim;

               (B) take such action in connection with contesting such claim as
               the Company shall reasonably request in writing from time to
               time, including, without limitation, accepting legal
               representation with respect to such claim by an attorney
               reasonably selected by the Company;

               (C) cooperate with the Company in good faith in order to
               effectively contest such claim; and

               (D) permit the Company to participate in any proceedings relating
               to such claim; provided, however, that the Company shall bear and
               pay directly all costs and expenses (including additional
               interest and penalties) incurred in connection with such contest
               and shall indemnify and hold the Executive harmless, on an after-
               tax basis, for any Excise Tax or income tax (including interest
               and penalties with respect thereto, other than interest or
               penalties imposed as a result of the failure of the Executive to
               file any tax return or pay any tax (except any such failure to
               pay tax in accordance with the terms hereof), required by
               applicable law to be filed or paid by the Executive) imposed as a
               result of such representation and payment of costs and expenses,
               Without limitation on the foregoing provisions of this subsection
               8(g)(iii), the Company shall control all proceedings taken in
               connection with such content and, at its sole option, may pursue
               or forego any and all administrative appeals, proceedings,
               hearings and conferences with the taxing authority in respect of
               such claim and may, at its sole option, either direct the
               Executive to pay the tax claimed and sue for a refund or contest
               the claim in any permissible manner, and the Executive agrees to
               prosecute such contest to a determination before any
               administrative tribunal, in a court of initial jurisdiction and
               in one or more appellate courts, as the Company shall determine;
               provided, however, that of the Company directs the Executive to
               pay such claim and sue for a refund, the Company shall advance
               the amount of such payment to the Executive, on an interest-free
               basis, and shall indemnify and hold the Executive harmless, on an
               after-tax basis, from any excise Tax or income tax (including
               interest or penalties with respect thereto, other than interest
               or penalties imposed as a result of the failure of the Executive
               to file any tax return or pay any tax (except any such failure to
               pay tax in accordance with the terms hereof), required by
               applicable law to be filed or paid by the Executive) imposed with
               respect to such advance or with respect to any imputed income
               with respect to such advance; and provided, further, that if the
               Executive is required to extend the statute of limitations to
               enable the Company to contest such
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                                                                              11

               claim, the Executive may limit this extension solely to such
               contested amount. The Company's control of the contest shall be
               limited to issues with respect to which a Gross-Up Payment would
               be payable hereunder and the Executive shall be entitled to
               settle or contest, as the case may be, any other issue raised by
               the Internal Revenue Service or any other taxing authority.

          (iv) If, after the receipt by the Executive of an amount advanced by
          the Company pursuant to subsection 8(g)(iii), the Executive becomes
          entitled to receive any refund with respect to such claim, the
          Executive shall (subject to the Company's complying with the
          requirements of subsection 8(g)(iii)) promptly pay to the Company the
          amount of such refund  (together with any interest paid or credited
          thereon after taxes applicable thereto). If, after the receipt by the
          Executive of an amount advanced by the Company pursuant to subsection
          8(g)(iii), a determination is made that the Executive shall not be
          entitled to any refund with respect to such claim and the Company does
          not notify the Executive in writing of its intent to contest such
          denial of refund prior to the expiration of thirty (30) days after
          such determination, then such advance shall be forgiven and shall not
          be required to be repaid and the amount of such advance shall offset,
          to the extent thereof, the amount of Gross-Up Payment required to be
          paid.

9.   Nondisclosure of Confidential Information; Non-Solicitation.
     -----------------------------------------------------------

     a. At any time during or for a period of three years after Executive's
     employment with the Company, Executive shall not, without the prior written
     consent of the Company, use, divulge, disclose or make accessible to any
     other person, firm, partnership, corporation or other entity any
     Confidential Information (as hereinafter defined) pertaining to the
     business of the Company or any of its subsidiaries, except (i) while
     employed by the Company, in the business of and for the benefit of the
     Company, or (ii) when required to do so by a court of competent
     jurisdiction, by any governmental agency having supervisory authority over
     the business of the Company, or by any administrative body or legislative
     body (including a committee thereof) with jurisdiction to order Executive
     to divulge, disclose or make accessible such information.  For purposes of
     this Section 8(a), "Confidential Information" shall mean non-public
     information concerning the financial data, strategic business plans, and
     other non-public, proprietary and confidential information of the Company,
     its subsidiaries, Blackstone (defined above), and their respective
     affiliates as in existence as of the date of Executive's termination of
     employment that, in any case, is not otherwise available to the public
     (other than by Executive's breach of the terms hereof).

     b. In the course of Executive's employment Executive will acquire knowledge
     of Confidential Information and trade secrets.  Executive acknowledges that
     the Confidential Information and trade secrets which the Company has
     provided and will provide to him could play a significant role were he to
     directly or indirectly be engaged in any business that competes with the
     Company or its subsidiaries.  Executive agrees that, without the prior
     written consent of the Company, (i) during his employment with the Company
     and
<PAGE>

                                                                              12

     for a period of two years thereafter he shall not, on his own behalf or
     on behalf of any person, firm or company, directly or indirectly, solicit
     the business of any person or entity that has been a client or customer of
     the Company or its subsidiaries at any time during the 12 months
     immediately preceding such solicitation, and (ii) during his employment
     with the Company or for a period of one year thereafter he shall not, on
     his own behalf or on behalf of any person, firm or company, directly or
     indirectly, solicit or offer employment to any person who has been employed
     by the Company, its subsidiaries, or Blackstone in an executive or
     management capacity at any time during the 12 months immediately preceding
     such solicitation.

     c. Executive and the Company agree that the foregoing covenants not to
     solicit are a reasonable covenant under the circumstances, and further
     agree that if in the opinion of any court of competent jurisdiction such
     restraints are not reasonable in any respect, such court shall have the
     right, power and authority to excise or modify such provision or provisions
     of these covenants as, to the court, shall appear not reasonable and to
     enforce the remainder of the covenant as so amended.

10.  Specific Performance.  Executive acknowledges and agrees that the Company's
     --------------------
remedies at law for a breach or threatened breach of any of the provisions of
Section 9 would be inadequate and, in recognition of this fact, Executive agrees
that, in the event of such a breach or threatened breach, in addition to any
remedies at law, the Company, without posting any bond, shall be entitled to
cease making any payments or providing any benefit otherwise required by this
Agreement and obtain equitable relief in the form of specific performance,
temporary restraining order, temporary or permanent injunction or any other
equitable remedy which may then be available.

11.  Miscellaneous.
     -------------

     a.  Governing Law.  This Agreement shall be governed by and construed in
         -------------
     accordance with the laws of the State of Missouri, without regard to
     conflicts of laws principles thereof.

     b.  Entire Agreement/Amendments.  This Agreement contains the entire
         ---------------------------
     understanding of the parties with respect to the employment of Executive by
     the Company.  There are no restrictions, agreements, promises, warranties,
     covenants or undertakings between the parties with respect to the subject
     matter herein other than those expressly set forth herein.  This Agreement
     may not be altered, modified, or amended except by written instrument
     signed by the parties hereto.  This Agreement supercedes all prior
     agreements and understandings (including verbal agreements) between
     Executive and the Company and/or its affiliates regarding the terms and
     conditions of Executive's employment with the Company and/or its affiliates

     c.  No Waiver.  The failure of a party to insist upon strict adherence to
         ---------
     any term of this Agreement on any occasion shall not be considered a waiver
     of such party's rights or deprive such party of the right thereafter to
     insist upon strict adherence to that term or any other term of this
     Agreement.
<PAGE>

                                                                              13

     d.  Severability.  In the event that any one or more of the provisions of
         ------------
     this Agreement shall be or become invalid, illegal or unenforceable in any
     respect, the validity, legality and enforceability of the remaining
     provisions of this Agreement shall not be affected thereby.

     e.  Assignment.  This Agreement shall not be assignable by Executive.  This
         ----------
     Agreement may be assigned by the Company to a company which is a successor
     in interest to substantially all of the business operations of the Company.
     Such assignment shall become effective when the Company notifies Executive
     of such assignment or at such later date as may be specified in such
     notice.  Upon such assignment, the rights and obligations of the Company
     hereunder shall become the rights and obligations of such successor
     company, provided that any assignee expressly assumes the obligations,
              --------
     rights and privileges of this Agreement.

     Mitigation.  If the Executive's employment hereunder is terminated for any
     ----------
     reason, the Executive shall not be subject to any duty or obligation to
     seek alternate employment or other sources of income or benefits, or to
     mitigate his damages, or to any similar duty or obligation, and, except as
     specifically provided with respect to the continuation of benefits, all
     payment and other obligations of the Company under this Agreement shall not
     be subject to any rights of set-off, duty to mitigate or other reduction,
     and shall be paid and performed in full notwithstanding any alternate
     employment or other sources of income or benefits obtained or received or
     receivable by the Executive.

     g.  Successors; Binding Agreement.  This Agreement shall inure to the
         -----------------------------
     benefit of and be binding upon personal or legal representatives,
     executors, administrators, successors, heirs, distributes, devises and
     legatees.

     h.  Notice.  For the purpose of this Agreement, notices and all other
         ------
     communications provided for in the Agreement shall be in writing and shall
     be deemed to have been duly given when delivered or mailed by United States
     registered mail, return receipt requested, postage prepaid, addressed to
     the respective addresses set forth below Agreement, or to such other
     address as either party may have furnished to the other in writing in
     accordance herewith, except that notice of change of address shall be
     effective only upon receipt.

     If to the Company:
     Clark Refining & Marketing, Inc.
     c/o Clark USA, Inc.
     8182 Maryland Avenue
     Clayton, Missouri 63105
     Attention:  Corporate Secretary
     If to Executive:
     To the most recent address of Executive set forth in the personnel records
     of the Company.
<PAGE>

                                                                              14

     i.  Withholding Taxes.  The Company may withhold from any amounts payable
         -----------------
     under this Agreement such Federal, state and local taxes as may be required
     to be withheld pursuant to any applicable law or regulation.

     j.  Counterparts.  This Agreement may be signed in counterparts, each of
         ------------
     which shall be an original, with the same effect as if the signatures
     thereto and hereto were upon the same instrument.

     k.  Legal and Professional Fees. The Corporation shall pay to the Executive
         ---------------------------
     all reasonable legal and professional fees and expenses incurred by the
     Executive in seeking to obtain or enforce any right or benefit provided by
     this Agreement.

          IN WITNESS WHEREOF, the parties hereto have duly executed this
Agreement as of the day and year first above written.

                              CLARK REFINING & MARKETING, INC.:

                              By:________________________
                              Name:
                              Title:

                              JEFFRY N. QUINN:

                              ___________________________
                              245 Litchford Court
                              Creve Coeur, Missouri 63141

<PAGE>

                                                                              15

                                   EXHIBIT A
          (Financial, Estate and Tax Preparation and Planning Services)

          .  Financial consulting services from AYCO, Inc.

          .  Estate planning work rendered by Gerald Zaft, Attorney-At-Law.

          .  Tax preparation and planning services for 2000 performed by AYCO,
             Inc.<PAGE>

                                                                   Exhibit 10.32

                                                                  EXECUTION COPY

================================================================================

                         SERVICES AND SUPPLY AGREEMENT

                                    BETWEEN

                       CLARK REFINING & MARKETING, INC.

                                      AND

                        PORT ARTHUR COKER COMPANY L.P.

                                August 19, 1999

================================================================================
<PAGE>

                               TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                                           Page
<S>                                                                                        <C>
ARTICLE 1.  DEFINITIONS                                                                      2
     Section 1.1      Definitions.........................................................   2
     Section 1.2      Other Definitional Provisions.......................................   2

ARTICLE 2.  GENERAL SCOPE OF CLARK R&M RESPONSIBILITIES...................................   2

ARTICLE 3.  ANCILLARY EQUIPMENT; SUPPLY AND SERVICES......................................   3
     Section 3.1      Crude Supply Management Services....................................   3
     Section 3.2      Docking, Pipeline Delivery, Handling and Storage of Crude Deliveries   4
     Section 3.3      Supply of Other Ancillary Equipment Feedstocks......................   4
     Section 3.4      Operation of Ancillary Equipment....................................   5
     Section 3.5      Processing of Clark R&M Products....................................   5
     Section 3.6      Title to Product Streams from Ancillary Equipment...................   6
     Section 3.7      Disposition of Product Streams from Ancillary Equipment.............   6

ARTICLE 4.  COKER COMPLEX; SUPPLY AND SERVICES............................................   6
     Section 4.1      Operation of Coker Complex..........................................   6
     Section 4.2      Processing of Clark R&M Products; Coker.............................   7
     Section 4.3      Processing of Clark R&M Products; Hydrocracker......................   7
     Section 4.4      Supply and Delivery of Other Feedstocks to Coker Complex............   8
     Section 4.5      Title to Product Streams from Coker Complex.........................   9
     Section 4.6      Disposition of Product Streams from Coker Complex...................   9

ARTICLE 5.  GENERAL SERVICES AND SUPPLIES.................................................   9
     Section 5.1      Construction Management.............................................   9
     Section 5.2      Contract Management.................................................   9
     Section 5.3      Maintenance Services................................................  10
     Section 5.4      Operation and Maintenance of Clark Equipment........................  10
     Section 5.5      Utility Services....................................................  11
     Section 5.6      Waste Management and Wastewater Services............................  12
     Section 5.7      Support Services....................................................  13
     Section 5.8      Personnel and Management Services...................................  13
     Section 5.9      Spare Parts.........................................................  14
     Section 5.10     Catalysts, Chemicals and Consumables................................  14
     Section 5.11     Quantity and Quality Control........................................  14
     Section 5.12     Environmental, Health and Safety Services...........................  16
     Section 5.13     Insurance Coverage..................................................  16
     Section 5.14     Licensing, Permits and Approvals....................................  16
     Section 5.15     Sulfur Recovery.....................................................  17
</TABLE>

                                       i-
<PAGE>

<TABLE>
<S>                                                                                         <C>
ARTICLE 6.  ANNUAL BUDGET AND OPERATING PLAN..............................................  17
     Section 6.1      Annual Budget.......................................................  17
     Section 6.2      Operating Adjustments...............................................  18
     Section 6.3      Quarterly Reports...................................................  19

ARTICLE 7.  PRICING AND PAYMENT...........................................................  20
     Section 7.1      Pricing of Services and Supplies....................................  20
     Section 7.2      Net Pricing and Statements..........................................  20
     Section 7.3      Payment Procedure...................................................  20
     Section 7.4      Alternative Pricing.................................................  20
     Section 7.5      Recordkeeping; Right to Audit; Access to Books and Records..........  21
     Section 7.6      Interest Rate for Late Payments.....................................  21

ARTICLE 8. DEFAULTS, REMEDIES AND TERMINATION.............................................  22
     Section 8.1      Clark R&M's Right to Terminate......................................  22
     Section 8.2      Coker Company's Right to Terminate and Other Remedies...............  22
     Section 8.3      Termination Option..................................................  23
     Section 8.4      Non-Exclusive Remedies; Specific Performance........................  23

ARTICLE 9.  TERM, AND COMMENCEMENT OF SERVICES............................................  23
     Section 9.1      Effectiveness; Term.................................................  23
     Section 9.2      End of Term Obligations.............................................  23

ARTICLE 10. REPRESENTATIONS AND WARRANTIES................................................  24
     Section 10.1     Representations and Warranties of the Coker Company.................  24
     Section 10.2     Representations and Warranties of Clark R&M.........................  25

ARTICLE 11. FURTHER AGREEMENTS............................................................  26
     Section 11.1     Intellectual Property; Confidentiality..............................  26
     Section 11.2     Force Majeure.......................................................  26
     Section 11.3     Cooperation with Other Parties......................................  26
     Section 11.4     Site Access.........................................................  26
     Section 11.5     Indemnity...........................................................  26
     Section 11.6     Dispute Resolution..................................................  27
     Section 11.7     Taxes...............................................................  28
     Section 11.8     Title to Property...................................................  28
     Section 11.9     Subcontractors......................................................  29

ARTICLE 12. MISCELLANEOUS.................................................................  29
     Section 12.1     Relationship of Parties.............................................  29
     Section 12.2     Third Party Beneficiaries...........................................  29
     Section 12.3     Clark R&M Warranties................................................  30
     Section 12.4     No Indirect Damages.................................................  30
     Section 12.5     Assignments.........................................................  30
     Section 12.6     Amendments..........................................................  31
     Section 12.7     Notices.............................................................  31
</TABLE>

                                      ii-
<PAGE>

<TABLE>
<S>                                                                                         <C>
     Section 12.8     GOVERNING LAW.......................................................  32
     Section 12.9     Submission to Jurisdiction; Forum Selection.........................  32
     Section 12.10    Appointment of Agent for Service of Process.........................  33
     Section 12.11    No Waiver...........................................................  33
     Section 12.12    Counterparts........................................................  33
     Section 12.13    Integration.........................................................  33
     Section 12.14    Severability........................................................  33
     Section 12.15    Headings............................................................  33
     Section 12.16    WAIVER OF JURY TRIAL................................................  34
 </TABLE>

                                     iii-
<PAGE>

APPENDIX A -- DEFINITIONS

SCHEDULES

Schedule 3.1     Crude Supply Management Services
Schedule 3.2     Dock, Pipeline and Storage Services
Schedule 3.3     Ancillary Equipment Feedstock Supply
Schedule 3.5     Clark Processing Fee -- Ancillary Equipment
Schedule 4.1     Coker Company Employees
Schedule 4.2     Clark R&M Processing Fee -- Coker
Schedule 4.3     Clark R&M Processing Fee -- Hydrocracker
Schedule 4.4     Hydrogen Supply Services
Schedule 5.1     Construction Management Services
Schedule 5.3     Maintenance Services
Schedule 5.5.1   Electricity
Schedule 5.5.2   Steam
Schedule 5.5.3   Natural and Fuel Gas
Schedule 5.5.4   Water
Schedule 5.5.5   Compressed Air
Schedule 5.5.6   Nitrogen
Schedule 5.5(b)  Utility Meters
Schedule 5.6     Waste Management and Wastewater Treatment Services
Schedule 5.7.1   Sulfur and Coke Transport Service
Schedule 5.7.2   Broad Band and Network Computing Services
Schedule 5.7.3   Radio and Phone Services
Schedule 5.7.4   Analytical Laboratory and Custody Transfer Services
Schedule 5.7.5   Security Services
Schedule 5.7.6   Other Support Service
Schedule 5.8.1   Operations Services
Schedule 5.8.2   Engineering Services
Schedule 5.8.3   Human Resources Services
Schedule 5.8.4   Accounting Services
Schedule 5.8.5   Administrative Services
Schedule 5.9     Coker Company Spares
Schedule 5.10    Catalyst and Caustic
Schedule 5.12.1  Environmental, Health and Safety Services
Schedule 5.12.2  Emergency Response Services
Schedule 5.13    Insurance
Schedule 5.14    Licenses, Permits and Approvals
Schedule 6.1     Annual Budget and Operating Plan

EXHIBITS

Exhibit A        Base Case Financial Model

                                      iv-
<PAGE>

          AGREEMENT FOR SUPPLY AND SERVICES, dated as of August 19, 1999,
between Clark Refining & Marketing, Inc., a Delaware corporation ("Clark R&M")
                                                                   ---------
and Port Arthur Coker Company L.P., a Delaware limited partnership (the "Coker
                                                                         -----
Company").
-------

                                    RECITALS

          WHEREAS, the Coker Company has entered into an EPC Contract with the
Contractor for the construction of the Coker Complex;

          WHEREAS, the Coker Company is causing the Coker Complex to be
constructed on land within the Refinery leased from Clark R&M, which Coker
Complex is intended to have at least the Coker Complex Design Capacity;

          WHEREAS, the Coker Company has leased the Ancillary Equipment located
within the Refinery, which Ancillary Equipment is being upgraded to have the
Crude Design Capacity to permit the production of at least the minimum volume of
feedstocks for the Coker Complex to operate at the Coker Complex Design
Capacity;

          WHEREAS, the Coker Company, pursuant to the Long-Term Oil Supply
Agreement, has access to Maya Crude Oil for processing through the Heavy Oil
Processing Facility;

          WHEREAS, Clark R&M has access to additional crude oil and other
feedstreams necessary to operate the Ancillary Equipment at the Crude Design
Capacity and the Coker Complex at the Coker Complex Design Capacity;

          WHEREAS, the Coker Company desires to deliver and Clark R&M desires to
purchase the Required Product Mix under the Product Purchase Agreement;

          WHEREAS, the Coker Company requires supplies and services in order to
operate the Ancillary Equipment and the Coker Complex and to produce the
Required Product Mix;

          WHEREAS, Clark R&M has the necessary technical and operational
capacity to deliver the such supplies and to provide such services required to
operate the Ancillary Equipment and the Coker Complex; and

          WHEREAS, the obligations of Clark R&M and the rights of the Coker
Company hereunder will be assigned to the Financing Parties as security in order
to finance the construction of the Coker Complex.

          NOW THEREFORE, for and in consideration of the mutual covenants,
premises and agreements set forth herein, and good and valuable consideration,
the receipt, sufficiency and adequacy of which are hereby acknowledged, the
parties hereto, intending to be legally bound, hereby agree as follows:
<PAGE>

                                                                               2
                            ARTICLE 1. DEFINITIONS

          Section 1.1   Definitions.  Except as contained in this Section 1.1 or
                        -----------
as otherwise defined herein, the capitalized terms used herein shall have the
respective meanings assigned thereto in Appendix A. For all purposes of this
Services and Supply Agreement, the following terms shall have the following
meanings:

          "Applicable Price" means, with respect to each Service or Supply to be
           ----------------
provided by Clark R&M hereunder during any monthly period, the total
reimbursable cost or fee due and payable by the Coker Company to Clark R&M for
such Service or Supply determined in accordance with the formula set forth under
the heading "Applicable Price" on the Schedule relating to such Service or
Supply, provided that to the extent any Service or Supply is not described in a
        --------
Schedule, the "Applicable Price" for such Service or Supply shall equal the
Permitted Reimbursable Expenses incurred by Clark R&M in providing such Service
or Supply.

          Section 1.2   Other Definitional Provisions.
                        -----------------------------

          (a) The words "hereof," "herein", "hereto" and "hereunder" and words
of similar import when used in this Services and Supply Agreement shall refer to
this Services and Supply Agreement as a whole and not to any particular
provision of this Services and Supply Agreement, and Article, Section and
Schedule references are to this Services and Supply Agreement unless otherwise
specified.

          (b) The meanings given to terms defined herein shall be equally
applicable to both the singular and plural forms of such terms.

            ARTICLE 2.  GENERAL SCOPE OF CLARK R&M RESPONSIBILITIES

          Clark R&M shall operate, manage and maintain all components of the
Ancillary Equipment and the Coker Complex and perform all other necessary
services (all of the foregoing, collectively, the "Services") and provide all
                                                   --------
necessary feedstocks and other materials (collectively, the "Supplies"), other
                                                             --------
than matters expressly stated herein to be the obligations of the Coker Company,
in order to generate the Required Product Mix on a continuous basis during the
term of this Services and Supply Agreement.  Clark R&M shall provide the
Services and Supplies in a prudent and efficient manner in compliance with the
following:

          (a)  Applicable Law;

          (b)  Prudent Industry Practice;

          (c)  requirements of applicable Warranties;

          (d)  applicable equipment manufacturers' recommended maintenance
procedures;
<PAGE>

                                                                               3

          (e)  the Operating Manuals, the Maintenance and Instruction Manuals
and the Mechanical Catalogs (each as defined in the EPC Contract);

          (f)  the EPC Contract and the other Project Documents; and

          (g)  the Financing Documents.

              ARTICLE 3. ANCILLARY EQUIPMENT; SUPPLY AND SERVICES

          Section 3.1  Crude Supply Management Services.  (a) Clark R&M shall
                       --------------------------------
coordinate the scheduling and execution of deliveries of the Contract Quantity
of Coker Company Maya to the Heavy Oil Processing Facility on behalf of the
Coker Company in accordance with the Long-Term Oil Supply Agreement and the
specifications set forth in Schedule 3.1.

          (b)  To the extent that the Coker Company does not have access under
the Long-Term Oil Supply Agreement to the volume of Maya Crude Oil required for
start-up and operation of the Heavy Oil Processing Facility during the Start-up
Period, Clark R&M shall supply the Coker Company with the additional volume of
Maya Crude Oil required for start-up and operation of the Heavy Oil Processing
Facility during such period and shall coordinate the scheduling and execution of
deliveries of such crude oil to the Heavy Oil Processing Facility on behalf of
the Coker Company, in accordance with the specifications set forth in Schedule
3.1. The Coker Company shall reimburse Clark R&M for the purchase price of such
crude oil and any reasonable administrative fees, financing fees or capital
allocation costs incurred by Clark R&M in procuring such crude oil by Clark R&M.

          (c)  Clark R&M shall procure on behalf of the Coker Company one or
more contracts for the supply of light crude oil necessary for the processing of
Coker Company Maya and shall coordinate the scheduling and execution of
deliveries of such crude oil to the Heavy Oil Processing Facility on behalf of
the Coker Company, in accordance with the specifications set forth in Schedule
3.1.

          (d)  Should the supply of Maya Crude Oil pursuant to the Long-Term Oil
Supply Agreement become unavailable for any reason, Clark R&M shall procure on
behalf of the Coker Company one or more alternative supplies of Maya Crude Oil
in amounts substantially equivalent to the Contract Quantity.  Clark R&M shall
coordinate the scheduling and execution of deliveries of such Maya Crude Oil to
the Heavy Oil Processing Facility in accordance with the specifications set
forth in Schedule 3.1.

          (e)  In connection with its obligations under this Section 3.1, Clark
R&M shall engage tankers on behalf, and at the expense, of the Coker Company for
the shipment of Coker Company Maya and Coker Company light crude oil. All
shipping contracts in connection therewith shall be entered into directly by the
Coker Company. Clark R&M shall ensure that all
<PAGE>

                                                                               4

such shipments of Coker Company Maya and Coker Company light crude oil are
adequately covered by marine cargo, casualty and other required insurance.  In
addition, in connection with such shipping, Clark R&M shall ensure that prior to
arrival at the Refinery Clark Maya will not be commingled with any shipment of
Coker Company Maya and Clark R&M light crude oil will not be commingled with any
shipment of Coker Company light crude oil.

          (f)  To the extent that any Clark R&M-owned crude oil is delivered to
the Refinery by the same pipeline as Coker Company-owned crude oil of the same
type, title to such commingled crude oil shall be allocated in accordance with
the respective volume of crude oil purchased by Clark R&M or the Coker Company
as evidenced by the bills of lading for such shipments.

          (g)  Clark R&M shall not grant any Lien on Clark R&M-owned crude oil
that is to be commingled with Coker Company-owned crude oil at the Refinery,
other than purchase money security interests necessary to secure the purchase
price of such Clark R&M-owned crude oil.

          Section 3.2  Docking, Pipeline Delivery, Handling and Storage of Crude
                       ---------------------------------------------------------
Deliveries.  (a) Clark R&M shall provide all docking, pipeline, handling and
----------
storage services necessary for the delivery of Coker Company Maya and other
Coker Company light crude oil to the Heavy Oil Processing Facility, in
accordance with the specifications set forth in Schedule 3.2.

          (b)  For the term of this Services and Supply Agreement, Clark R&M
shall (i) maintain the Marine Dock and Terminaling Agreement (as such term is
defined in the Common Security Agreement) in effect and comply with all of its
material obligations thereunder and (ii) make advance payments to Sun Pipe Line
Company every thirty (30) days in amounts equal to the maximum amount that Clark
R&M estimates, in its reasonable good faith judgment, will be due and payable by
Clark R&M to Sun Pipe Line Company pursuant to the Marine Terminaling Agreement
in the next succeeding thirty (30) days.

          Section 3.3  Supply of Other Ancillary Equipment Feedstocks.  (a)
                       ----------------------------------------------
Clark R&M shall coordinate the scheduling and execution of deliveries of
Hydrogen needed to process Coker Company Maya and light crude oil through the
Ancillary Equipment on behalf of the Coker Company in accordance with the
Hydrogen Supply Agreement and shall otherwise perform the Coker Company's
obligations (other than payment to obligations) and exercise its rights under
the Hydrogen Supply Agreement, in accordance with Schedule 4.3.

          (b)  Clark R&M shall supply and the Coker Company shall purchase all
other feedstocks (including any additional hydrogen not available to the Coker
Company under the Hydrogen Supply Agreement) necessary for the processing of
Coker Company Maya and Coker Company light crude oil through the Ancillary
Equipment and Clark R&M shall deliver such products to the Ancillary Equipment,
in accordance with the specifications set forth in Schedule 3.3 and Schedule
4.4.
<PAGE>

                                                                               5

          (c)  Clark R&M shall maintain the Clark Hydrogen Supply Contract in
effect for the term of this Services and Supply Agreement and shall comply with
all of its material obligations thereunder.

          Section 3.4  Operation of Ancillary Equipment.  Clark R&M shall
                       --------------------------------
operate and maintain the Ancillary Equipment and manage the processing of Maya
Crude Oil and other feedstreams thereby on behalf of itself and the Coker
Company.

          Section 3.5  Processing of Clark R&M Products.  (a) Prior to the
                       --------------------------------
Start-up Date, Clark R&M shall have the right to process Clark R&M-owned crude
oil through the Ancillary Equipment; provided that (i) all operating expenses
                                     --------
related thereto shall be for the account of, and exclusively paid by,  Clark R&M
and (ii) the processing of Clark R&M-owned crude oil pursuant to this clause (a)
shall (x) in no way interfere with the timely performance of the Lessor
Ancillary Equipment Upgrade, the construction of the Coker Complex by the
Contractor or the achievement of the Guranteed Values by the Guaranteed
Performance Dates (as such terms are defined in the EPC Contract) or (y) not
adversely affect the reliability or the useful life of the Ancillary Equipment.
The parties agree that consideration for the processing rights granted Clark R&M
under this Section 3.5(a) has been given to the Coker Company in the form of a
reduction in the rent payable that would otherwise be payable pursuant to
Section 13.1(a)(i) of the Ancillary Equipment Site Lease.

          (b)  After Final Completion, subject to the terms and conditions
hereinafter set forth, Clark R&M shall have the right (the "Excess Crude
Capacity Option") each calendar quarter during the term of this Service and
Supply Agreement to require the Coker Company to process Clark R&M-owned crude
oil and other feedstreams equal to the Excess Crude Capacity for each day during
such calendar quarter.

          (c)  If Clark R&M shall not have given the Coker Company written
notice at least thirty days prior to any calendar quarter that it does not
intend to exercise its Excess Crude Capacity Option for the succeeding calendar
quarter, Clark R&M shall be deemed to have exercised such right and shall pay
the Coker Company for the processing of Clark R&M-owned crude oil and other
feedstreams equal to the Excess Crude Capacity for each day during such calendar
quarter in accordance with the formulas set forth on Schedule 3.5.

          (d)  If Clark R&M chooses not to exercise its Excess Crude Capacity
Option in any calendar quarter, the Coker Company may sell such processing right
(or portion of such right) to an alternative purchaser and Clark R&M agrees to
provide such alternative purchaser and/or the Coker Company with such Services
and Supplies hereunder as may be required to process crude oil and other
feedstreams for such party through the Ancillary Equipment.

          (e)  If Clark R&M chooses to exercise its Excess Crude Capacity Option
in any calendar quarter, the Coker Company agrees to process Clark R&M-owned
crude oil and other feedstreams through the Ancillary Equipment or through any
other appropriate equipment to which the Coker Company may have access, provided
                                                                        --------
that (i) if the Coker Company chooses to process such Clark R&M-owned crude oil
and other feedstreams through the Ancillary
<PAGE>

                                                                               6

Equipment, such processing will not interrupt, reduce or otherwise materially
interfere with the processing of Coker Company Maya during such calendar quarter
or (ii) if the Coker Company chooses to process such Clark R&M-owned crude oil
and other feedstreams through alternative equipment, such processing will not
materially affect the expected product yields from such crude oil and other
feedstreams.

          Section 3.6  Title to Product Streams from Ancillary Equipment.  Title
                       -------------------------------------------------
to product streams resulting from the processing of Coker Company Maya and other
Coker Company-owned crude oil through the Ancillary Equipment shall be
determined on a pro rata basis in proportion to the relative volume of Coker
Company-owned crude oil and other crude oil processed through the Ancillary
Equipment for Clark R&M (or for other third parties if Clark R&M does not
exercise its Excess Crude Capacity Option), in accordance with the
specifications and formulas under the heading "Quantity" on the Schedules to the
Product Purchase Agreement (it being understood that Clark R&M shall have title
to those product streams resulting from the processing of Clark R&M-owned
feedstreams through the Ancillary Equipment pursuant to Section 3.5).

          Section 3.7  Disposition of Product Streams from Ancillary Equipment.
                       -------------------------------------------------------

          (a)  Clark R&M shall determine the portion, if any, of Coker Company-
owned VGO and Clark R&M-owned VGO produced by the Crude Unit that is required to
fill the remaining Excess Hydrocracker Capacity of the Hydrocracker on any day
in accordance with the provisions of Section 4.3 and shall manage the delivery
of any such VGO to the Hydrocracker on behalf of the Coker Company and itself.

          (b)  Clark R&M shall manage the delivery of VTBs from the Ancillary
Equipment to the Coker on behalf of the Coker Company and itself.

          (c)  Clark R&M shall manage the delivery of all Products from the
Ancillary Equipment (including all Coker Company-owned VGO not delivered to the
Hydrocracker pursuant to clause (a) above) that are to be sold under the
Products Purchase Agreement in accordance with such agreement.

          (d)  Clark R&M shall deliver all other Clark R&M-owned product streams
(other than VTBs and VGO to be delivered to the Coker Complex) to the battery
limits of the Ancillary Equipment and shall take possession and control all such
Clark R&M-owned product streams delivered to the battery limits of the Ancillary
Equipment.

                 ARTICLE 4.  COKER COMPLEX; SUPPLY AND SERVICES

          Section 4.1  Operation of Coker Complex.
                       --------------------------

          (a)  The Coker Company shall employ the roster of personnel with the
job descriptions listed on Schedule 4.1; provided, however, that the Coker
                                         --------  -------
Company may reduce the
<PAGE>

                                                                               7

number of such employees to the extent (i) that changes in technology or
automation opportunities allow a reduced number of Coker Company to perform such
job descriptions in a more cost effective manner and (ii) permitted by the
Financing Documents.

          (b)  Clark R&M shall supervise and train the employees referred to in
clause (a) above and shall otherwise operate and maintain the Coker Complex and
manage the processing of VTBs, VGO, LCO and other feedstreams thereby on behalf
of the Coker Company.

          (c)  Clark R&M shall operate the Coker Complex in accordance with all
of the terms and conditions set forth in the EPC Contract.

          Section 4.2  Processing of Clark R&M Products; Coker.  (a)  Subject to
                       ---------------------------------------
the terms and conditions hereinafter set forth and to Section 6.2(d), Clark R&M
shall have the right (the "Excess Coker Capacity Option") each calendar quarter
during the term of this Service and Supply Agreement to require the Coker
Company to process Clark R&M-owned VTBs and other feedstreams equal to the
Excess Coker Capacity each day during such calendar quarter.

          (b)  If Clark R&M shall not have given the Coker Company written
notice at least thirty days prior to any calendar quarter that it does not
intend to exercise its Excess Coker Capacity Option for the succeeding calendar
quarter, Clark R&M shall be deemed to have exercised such right and shall pay
the Coker Company for the processing of VTBs and other feedstreams equal to the
Excess Coker Capacity each day during such calendar quarter in accordance with
the formula set forth on Schedule 4.2.

          (c)  If Clark R&M chooses not to exercise its Excess Coker Capacity
Option in any calendar quarter, the Coker Company may sell such processing right
(or portion of such right) to an alternative purchaser and Clark R&M agrees to
provide such alternative purchaser and/or the Coker Company with such Services
and Supplies hereunder as may be required to process VTBs and other feedstreams
for such party through the Coker.

          (d)  If Clark R&M chooses to exercise its Excess Coker Capacity Option
in any calendar quarter, the Coker Company agrees to process Clark R&M-owned
VTBs and other feedstreams through the Coker or through any other appropriate
equipment to which the Coker Company may have access, provided that (i) if the
                                                      --------
Coker Company chooses to process such Clark R&M-owned feedstreams through the
Coker, such processing will not interrupt, reduce or otherwise materially
interfere with the processing of Coker Company VTBS during such calendar quarter
or (ii) if the Coker Company chooses to process such Clark R&M-owned feedstreams
through alternative equipment, such processing will not materially affect the
expected product yields from such feedstreams.

          Section 4.3  Processing of Clark R&M Products; Hydrocracker.  (a)
                       ----------------------------------------------
Subject to the terms and conditions hereinafter set forth, Clark R&M shall have
the right (the "Excess Hydrocracker Capacity Option") each calendar quarter
during the term of this Service and Supply Agreement to require the Coker
Company to process Clark R&M-owned feedstreams up to an amount equal to the
Excess Hydrocracker Capacity each day during such calendar quarter.
<PAGE>

                                                                               8

          (b)  If Clark R&M shall not have given the Coker Company written
notice at least thirty days prior to any calendar quarter that it does not
intend to exercise its Excess Hydrocracker Capacity Option for the succeeding
calendar quarter, Clark R&M shall be deemed to have exercised such right and
shall pay the Coker Company for the processing of Clark R&M-owned feedstreams
during such calendar quarter in accordance with the formulas set forth on
Schedule 4.3.

          (c)  If Clark R&M chooses to exercise its Excess Hydrocracker Capacity
Option in any calendar quarter, the Coker Company agrees to process the volume
of Clark R&M-owned LCO, VGO and other feedstreams designated by Clark R&M each
day up to the Excess Hydrocracker Capacity for such day through the Hydrocracker
or through any other appropriate equipment to which the Coker Company may have
access, provided that (i) if the Coker Company chooses to process such Clark
        --------
R&M-owned feedstreams through the Hydrocracker, such processing will not
interrupt, reduce or otherwise materially interfere with the processing of Coker
Company VGO produced by the Coker during such calendar quarter or (ii) if the
Coker Company chooses to process such Clark R&M-owned feedstreams through
alternative equipment, such processing will not materially affect the expected
product yields from such feedstreams.  To the extent that Clark R&M does not
exercise its right to use all Excess Hydrocracker Capacity on any day during
such calendar quarter, Clark R&M shall ensure that pro rata portions of Coker
Company-owned and Clark R&M-owned VGO produced by the Crude Unit on such day are
used to fill the remaining Excess Hydrocracker Capacity of the Hydrocracker.
Clark R&M shall pay the Coker Company for all such Clark R&M-owned VGO processed
by the Hydrocracker in accordance with the formulas set forth on Schedule 4.3.

          (d)  If Clark R&M chooses not to exercise its Excess Hydrocracker
Capacity Option in any calendar quarter, the Coker Company may sell such
processing right (or portion of such right) to an alternative purchaser or
direct Clark R&M to ensure that the Excess Hydrocracker Capacity (or any portion
thereof) is used to process Coker Company VGO produced by the Crude Unit.  In
either case, Clark R&M shall provide the Coker Company and/or such alternative
purchaser with such Services and Supplies hereunder as may be required to
process VGO or other feedstreams for such party through the Hydrocracker.

          Section 4.4  Supply and Delivery of Other Feedstocks to Coker Complex.
                       --------------------------------------------------------

          (a)  Clark R&M shall coordinate the scheduling and execution of
deliveries of Hydrogen needed to process Coker Company-owned VTBs and VGO by the
Coker Complex on behalf of the Coker Company in accordance with the Hydrogen
Supply Agreement and shall otherwise perform the Coker Company's obligations
(other than payment to obligations) and exercise its rights under the Hydrogen
Supply Agreement, in accordance with Schedule 4.4.

          (b)  Clark R&M shall supply and the Coker Company shall purchase all
other feedstocks (including any additional hydrogen not available under the
Hydrogen Supply Agreement) necessary to process Coker Company-owned VTBs, VGO
and other feedstreams through the Coker Complex and shall manage the delivery of
such products to the Coker Complex, in accordance with the specifications set
forth in Schedule 4.4.
<PAGE>

                                                                               9

          (c)  Clark R&M shall provide at its expense all hydrogen and other
feedstocks necessary to process any Clark R&M-owned VTBs, LCO and other
feedstreams through the Coker Complex and shall deliver such products to the
Coker Complex.

          Section 4.5  Title to Product Streams from Coker Complex.  Title to
                       -------------------------------------------
product streams resulting from the processing of Coker Company-owned VTBs and
VGO through the Coker Complex shall be determined on a pro rata basis in
proportion to the relative volume of Coker Company-owned VTBs and VGO and other
VTBs and VGO processed by the Coker Complex for Clark R&M (or for other third
parties if Clark R&M has not exercised its Excess Coker Capacity Option and/or
its Excess Hydrocracker Capacity Option, as the case may be), in accordance with
the specifications and formulas under the heading "Quantity" on the Schedules to
the Product Purchase Agreement (it being understood that Clark R&M shall have
title to any product streams resulting from the processing of Clark R&M-owned
LCO and other Clark R&M-owned product streams through the Coker Complex pursuant
to Section 4.2).

          Section 4.6  Disposition of Product Streams from Coker Complex.  (a)
                       -------------------------------------------------
Clark R&M shall coordinate and manage the delivery of Coker Company Products
from the Coker Complex, in accordance with the Product Purchase Agreement.

          (b)  Clark R&M shall deliver all Clark R&M-owned product streams from
the Coker Complex to the battery limits of the Coker Complex and shall take
possession and control all such Clark R&M-owned product streams delivered to the
battery limits of the Coker Complex.

                    ARTICLE 5.  GENERAL SERVICES AND SUPPLIES

          Section 5.1  Construction Management.
                       -----------------------

          (a)  Clark R&M (i) shall manage and supervise the construction of the
Coker Complex by the Contractor and cooperate with the Independent Engineer to
ensure the construction of the Coker Complex in accordance with the EPC Contract
and (ii) shall fulfill all obligations, and perform all functions, of the Coker
Company under the EPC Contract, other than payment obligations of the Coker
Company thereunder including, without limitation, those listed on Schedule 5.1
hereto.

         (b)   Without limiting the generality of the foregoing clause, Clark
R&M agrees to schedule, coordinate, manage and perform all start-up and
performance testing obligations of the Coker Company under the EPC Contract and
take such other steps as are necessary to cause the Coker Complex to achieve the
Guaranteed Values by the Guaranteed Performance Dates (as such terms are defined
in the EPC Contract).

          Section 5.2  Contract Management.  (a) Clark R&M shall supervise and
                       -------------------
monitor the performance by counterparties (other than itself) to all Coker
Company contracts (other than the Financing Documents) and the Coker Company's
relationships with such parties,
<PAGE>

                                                                              10

including, without limitation, (i) the adequacy and timeliness of the
performance by such counterparties, (ii) timely assertion of the Coker Company's
rights under such contracts, (iii) enforcement of contractor, subcontractor and
vendor warranties and guaranties in connection therewith, and (iv) management of
dispute resolution and/or litigation in connection therewith.

          (b)  Clark R&M's performance of its obligations under clause (a) above
shall be subject to the on-going supervision and control of the Coker Company.
In connection with its obligations under Section 6.3, Clark R&M shall provide
the Coker Company quarterly reports describing actions taken by Clark R&M in the
previous calendar quarter in connection with the performance of its obligations
under clause (a) above.

          Section 5.3  Maintenance Services
                       --------------------

          (a)  In compliance with Applicable Law and Prudent Industry Practice,
Clark R&M shall provide all maintenance services, materials and labor necessary
and advisable to efficiently operate and maintain the Heavy Oil Processing
Facility and the on-going production of the Required Product Mix, including,
without limitation, the services specified on Schedule 5.3. The Coker Company
shall pay for such Services in accordance with the pricing formula set forth in
Schedule 5.3. Notwithstanding the foregoing, the parties agree that certain
capital repairs and similar maintenance services with respect to the Ancillary
Equipment shall be provided at the expense of Clark R&M pursuant to Section 9.1
of the Ancillary Equipment Lease.

          (b)  Clark R&M shall regularly update and implement an equipment
upgrade, repair and preventive maintenance program with respect to the Heavy Oil
Processing Facility that meets the requirements of (i) Applicable Law, (ii) the
Permits, (iii) specifications of equipment manufacturers, (iv) the
recommendations of the Contractor and (v) the Financing Documents.

          (c)  Notwithstanding the foregoing provisions of this Section 5.3,
Clark R&M shall not be required to fund or commit to fund any capital
expenditures in connection with its obligations under this Section 5.3 that are
in excess of amounts available in the Coker Company's Major Maintenance Account
(as such term is defined in the Financing Documents), unless the Coker Company
has demonstrated that it is capable of compensating Clark R&M for such capital
expenditures and that payment of such compensation is permitted under the
Financing Documents.

          Section 5.4  Operation and Maintenance of Clark Equipment.
                       --------------------------------------------

          (a)  In compliance with Applicable Law and Prudent Industry Practice,
throughout the term of this Services and Supply Agreement Clark R&M shall
operate and maintain all pipelines, interconnections and other Clark Equipment
as necessary for the efficient operation of the Heavy Oil Processing Facility
and the on-going production of the Required Product Mix.  Without limiting the
generality of the foregoing, Clark R&M shall provide all maintenance services,
equipment improvements, personnel and other resources that are necessary for the
Clark Equipment to (i) generate the feedstocks for the Heavy Oil Processing
Facility that
<PAGE>

                                                                              11

this Services and Supply Agreement contemplates will be generated by the Clark
Equipment, (ii) process intermediate products from the Heavy Oil Processing
Facility into saleable products, (iii) continue to operate the remainder of the
Refinery and produce intermediate and saleable products and (iv) otherwise
provide the Services and Supplies that this Services and Supply Agreement
contemplates will be provided by Clark Equipment.

          (b)  Clark R&M shall coordinate the scheduling and performance of all
necessary maintenance, including turnarounds and unscheduled unit shutdowns, at
the Refinery to ensure on-going production of the Required Product Mix.

          Section 5.5  Utility Services.  (a) Clark R&M shall provide the
                       ----------------
following utility services, each in accordance with the more detailed
description on the Schedule referenced opposite such Service on the chart below,
to the Coker Company for the operation of the Heavy Oil Processing Facility. The
Coker Company shall reimburse Clark R&M for the cost of each such Service
(except for potable water, the cost for which is included in the rents payable
by the Coker Company under the Coker Complex Ground Lease and the Ancillary
Equipment Site Lease) in accordance with the formulas set forth in the Schedule
relating thereto:

               Utility                             Schedule
               -------                             --------

               Electricity                      Schedule 5.5.1
               Steam                            Schedule 5.5.2
               Natural and Fuel Gas             Schedule 5.5.3
               Water                            Schedule 5.5.4
               Compressed Air                   Schedule 5.5.5
               Nitrogen                         Schedule 5.5.6

Notwithstanding anything in the foregoing to the contrary, in the event the
Clark Hydrogen Supply Agreement is terminated or expires prior to its stated
term, (i) the Coker Company shall have no obligation to purchase its full
requirements for electricity or steam from Clark R&M and (ii) to the extent that
the Coker Company purchases any portion of its requirements of steam and
electricity from Air Products pursuant to the Hydrogen Supply Agreement, Clark
R&M shall provide the Coker Company with any additional steam or electricity
required for operation of the Heavy Oil Processing Facility and the Coker
Company shall reimburse Clark R&M for the costs of such Services in accordance
with the formulas set forth in Schedule 5.5.1 or Schedule 5.5.2, as the case may
be.

          (b)  In order to properly measure each Service provided to the Coker
Complex pursuant to clause (a) above, Clark R&M shall (i) utilize the meter(s)
or calculation method, as the case may be, described under the heading
"Metering/Measurement Methodology for Services to the Coker Complex" on the
Schedule relating to such Service and/or Schedule 5.5(b), as the case may be,
(ii) operate and maintain all metering devices described on such Schedules and
(iii) test the accuracy of such meters and the calculation methods in accordance
with its regular practices.
<PAGE>

                                                                              12

          (c)  If  any test described in clause (b)(iii) of this Section 5.5
discloses that any metering device or calculation method related to the Services
provided pursuant to clause (a) above is materially inaccurate, Clark R&M shall
(i) promptly take such steps as necessary to correct such inaccuracy by
calibrating the applicable meters and/or adjusting the applicable calculation
method and (ii) adjust charges (except with respect to potable water) to the
Coker Company under Article 7 in order to compensate for the effect of such
inaccuracy on any charges related to the period extending back to the prior
accuracy test.  For the purpose of calculating the amount of such adjustment,
the parties agree to assume that the inaccuracy occurred at the midpoint in time
between the prior accuracy test and the current accuracy test; provided,
                                                               --------
however, that if the time that such inaccuracy occurred can be ascertained by
-------
Prudent Industry Practice, the amount of the applicable adjustment shall be
based on such time.

          (d)  Clark R&M shall preserve all its original test data, charts and
other records related to testing and measurements described in this Section for
a period of at least two years and make such records available, together with
calculations therefrom, for inspection or verification by the Coker Company.

          (e)  Should Clark R&M determine, in its reasonable judgment, that
additional and/or replacement meters are necessary to more accurately measure
the utilities described in this Section 5.5, it shall propose a metering upgrade
plan as part of the Annual Budget and Operating Plan for the Heavy Oil
Processing Facility.

          (f)  The agreement and obligation of Clark R&M to provide electric
utilities and electric service, natural gas and gas service and potable water
and water service under this Section 5.5 and sanitary sewage service under
Section 5.6 (each a "Regulated Utility") to the Coker Company is incident to,
                     -----------------
dependent upon and inseparable from the landlord/tenant relationship established
by the Coker Complex Ground Lease and the Ancillary Site Equipment Lease, and
such obligation shall continue only for the Coker Complex Ground Lease Term and
the Ancillary Site Lease Term, respectively, and the existence of such
landlord/tenant relationships between Clark R&M as landlord and the Coker
Company as tenant under such leases.  The provisions of this Services and Supply
Agreement and the Ancillary Equipment Operating Fee are intended only to provide
a mechanism for Clark R&M to recover from the Coker Company the costs of
providing such Regulated Utilities described herein (and it is not intended that
Clark R&M shall make a profit by providing such utilities or utility services).
The Coker Company acknowledges, understands and agrees that none of the
Regulated Utilities provided by Clark R&M to the Coker Company may be sold or
resold by the Coker Company, and none of such Regulated Utilities may be used by
any other party or for any purposes other than in connection with its tenancies
under the Coker Complex Ground Lease and the Ancillary Site Equipment Lease,
respectively.

          Section 5.6  Waste Management and Wastewater Services.  Clark R&M
                       ----------------------------------------
shall provide all collection, processing, treatment, transportation, storage,
disposal and recycling of waste generated by the Heavy Oil Processing Facility
and all rain water runoff, cooling tower blow down, sanitary sewage, recovered
oil, recovered residuals and all other hazardous and solid
<PAGE>

                                                                              13

waste originating at the Heavy Oil Processing Facility in accordance with
Schedule 5.6.  The Coker Company shall reimburse Clark R&M for the costs of such
Services (except sanitary sewage service, the costs for which are included in
the rents payable by the Coker Company under the Coker Complex Ground Lease and
the Ancillary Equipment Site Lease) in accordance with the formulas set forth in
Schedule 5.6.

          Section 5.7  Support Services.  Clark R&M shall provide the following
                       ----------------
additional support services, each as more particularly described on the Schedule
opposite such Service on the chart below, as necessary for the operation of the
Heavy Oil Processing Facility.  The Coker Company shall pay for each such
Service in accordance with the pricing formulas set forth in the Schedule
relating to such Service:

               Support Service                              Schedule
               ---------------                              --------

               Sulfur and Coke Transport Service            Schedule 5.7.1
               Broad Band and Network Computing Services    Schedule 5.7.2
               Radio and Phone Services                     Schedule 5.7.3
               Analytical Laboratory and
                 Custody Transfer Services                  Schedule 5.7.4
               Security Services                            Schedule 5.7.5
               Other Support Service                        Schedule 5.5.6

          Section 5.8  Personnel and Management Services.
                       ---------------------------------

          (a)  Clark R&M shall hire or provide all additional labor (other than
Coker Company employees) required to operate the Coker Complex and all labor and
professional, supervisory and management personnel as are required to operate
the Ancillary Equipment and to otherwise perform its obligations hereunder
including, without limitation, personnel required to provide the following
Services, each more particularly described on the Schedule referenced opposite
such Service on the chart below:

               Operations Services                        Schedule 5.8.1
               Engineering Services                       Schedule 5.8.2
               Human Resources Services                   Schedule 5.8.3
               Accounting Services                        Schedule 5.8.4
               Administrative Services                    Schedule 5.8.5

          (b)  All personnel described in clause (a) above shall be employees of
Clark R&M for all purposes, including compensation, payroll, income and other
tax liabilities, pension contributions, insurance and workers compensation.
Clark R&M shall ensure that all key personnel are qualified and experienced in
operating facilities such as the Refinery.

          (c)  To the extent the Coker Company requires additional personnel to
fulfill its obligation under clause (a) of Section 4.1, Clark R&M shall assist
the Coker Company in
<PAGE>

                                                                              14

hiring and training personnel that are qualified and experienced in operating
facilities such as the Refinery.

          Section 5.9  Spare Parts.
                       -----------

          (a)  Pursuant to the Bill of Sale, the Coker Company is purchasing the
spare parts listed on Schedule 5.9 from Clark R&M (the "Existing Spare Parts").
                                                        --------------------
In accordance with Section 2.38 of the EPC Contract and its obligations under
Sections 5.1 and 5.2, Clark R&M shall procure additional spare parts on behalf
of the Coker Company or instruct the Contractor to purchase such spare parts on
behalf of the Coker Company (all such spare parts together with the Existing
Spare Parts, the "Coker Company Spare Parts").  Clark R&M shall use its best
                  -------------------------
efforts to ensure that all purchases of Coker Company Spare Parts are made at
competitive rates.  At all times during the term of this Services and Supply
Agreement, Clark R&M shall maintain a complete inventory of all Coker Company
Spare Parts and shall manage and store such spare parts in a manner that ensures
that the Coker Company Spare Parts are at all time separate from the Common
Spare Parts and identifiable as property of the Coker Company.  The Coker
Company shall reimburse Clark R&M for all Coker Company Spare Parts procured by
Clark R&M.

          (b)  Clark R&M shall acquire, manage and store all other spare parts
necessary for the operation of the Heavy Oil Processing Facility and the
performance of Clark R&M's obligations hereunder (the "Common Spare Parts").
                                                       ------------------
The Coker Company shall reimburse Clark R&M for the cost of Common Spare Parts
utilized in connection with the Coker Complex.

          (c)  Clark R&M shall (i) ensure that all Coker Company Spare Parts are
new and that all spare parts described in this Section 5.9, including Coker
Company Spare Parts, are of good quality and free from defects, (ii) utilize all
such spare parts in accordance with manufacturer and supplier warranties and
recommendations, and (iii) assign to the Coker Company any warranties it obtains
in procuring Coker Company Spare Parts and other spare parts or equipment that
are utilized in connection with the Coker Complex.

          Section 5.10  Catalysts, Chemicals and Consumables.  Clark R&M shall
                        ------------------------------------
supply all catalysts, chemicals and other consumable materials necessary for the
operation of the Heavy Oil Processing Facility and the performance of its
obligations hereunder, including, without limitation those more particularly
described on Schedule 5.10.  The Coker Company shall pay Clark R&M for such
materials, in accordance with the pricing formulas set forth in Schedule 5.10.

          Section 5.11  Quantity and Quality Control.
                        ----------------------------

          (a)  In order to properly measure each product to be delivered under
this Services and Supply Agreement and the Product Purchase Agreement in
accordance with Prudent Industry Practice, Clark R&M shall (i) utilize the
meter(s) or calculation method, as the case may be, described under the headings
"Quantity" and "Quantity Measurement" on the Schedules to the Product Purchase
Agreement or the heading "Metering/Measurement Methodology" on the
<PAGE>

                                                                              15

Schedules to the Services and Supply Agreement relating to such product, (ii)
operate and maintain all metering devices described on such Schedules and (iii)
test the accuracy of such meters and the calculation methods as described in
clause (d) below.

          (b)  Clark R&M shall implement, manage and maintain a system of
quality control and sampling to ensure that each product delivered under this
Services and Supply Agreement complies with (i) the specifications in the
Schedules and (ii) the Product Purchase Agreement, as the case may be.

          (c)  Every three days, Clark R&M shall provide the Coker Company with
the product quantity and quality information necessary for the Coker Company to
bill Clark R&M under Section 4.2 of the Product Purchase Agreement.

          (d)  In accordance with its regular practices, Clark R&M shall test
the accuracy of the meters and calculation methods described in clause (a) above
through a combination of field verifications of meters and material balances of
Refinery units. The Coker Company may from time to time request Clark R&M to
conduct additional accuracy tests, at the Coker Company's expense. If any
material inaccuracy is disclosed by any such test, Clark R&M shall (i) promptly
take such steps as necessary to correct such inaccuracy by calibrating meters
and/or adjusting the applicable calculation method and (ii) as applicable,
adjust charges to the Coker Company under Article 7 and/or provide the Coker
Company the information to adjust charges to Clark R&M under Section 4.2 of the
Products Purchase Agreement in order to compensate for the effect of such
inaccuracy on any charges related to the period extending back to the prior
accuracy test. For the purpose of calculating the amount of such adjustment, the
parties agree to assume that the inaccuracy occurred at the midpoint in time
between the prior accuracy test and the current accuracy test; provided,
                                                               --------
however, that if the time that such inaccuracy occurred can be ascertained by
-------
Prudent Industry Practice, the amount of the applicable adjustment shall be
based on such time.

          (e)  Clark R&M shall preserve all its original test data, charts and
other records related to the quantity and quality measurements described in this
Section for a period of at least two years and make such records available,
together with calculations therefrom, for inspection or verification by the
Coker Company.

          (f)  Should Clark R&M determine, in its reasonable judgment, that
additional and/or replacement meters are necessary to more accurately measure
the Products, it shall propose a metering upgrade plan as part of the Annual
Budget and Operating Plan for the Heavy Oil Processing Facility.

          (g)  To the extent that any meters described on the Exhibits to the
Product Purchase Agreement are designated "XX-XXX", the Coker Company and Clark
R&M shall promptly replace such designation with meter identification numbers
upon completion of design engineering relating to such meter.
<PAGE>

                                                                              16

          Section 5.12  Environmental, Health and Safety Services.
                        -----------------------------------------

          (a)  Clark R&M shall be solely responsible for initiating, maintaining
and supervising all environmental, health and safety precautions and programs in
connection with the construction, operation and maintenance of the Heavy Oil
Processing Facility and the performance of its duties hereunder and shall
maintain the safety of the Heavy Oil Processing at a level consistent with
Applicable Law and Prudent Industry Practice, in accordance with Schedule
5.12.1.

          (b)  Clark R&M shall provide the emergency response services described
on Schedule 5.12.2. If an emergency conditions arises, Clark R&M may take
whatever steps it deems necessary and/or appropriate consistent with Prudent
Industry Practice and Applicable Law to preserve and protect any portion of the
Refinery and persons at the Refinery and to overcome the emergency condition,
restore the Refinery and continue performance of its duties hereunder. To the
extent such emergency action involves the Heavy Oil Processing Facility, the
Coker Company will reimburse Clark R&M for its pro rata share of expenses
incurred in connection with such action, in accordance with Schedule 5.12.2.

          Section 5.13  Insurance Coverage.
                        ------------------

          (a)  Clark R&M shall purchase and maintain, on behalf of the Coker
Company, the insurance coverage specified in Schedule 5.13 for the Heavy Oil
Processing Facility. Clark R&M shall cause such insurance coverage to (i) be
available at such times and in such amounts as required by the Financing
Documents, (ii) comply in form and substance to the requirements of the
Financing Documents, including, without limitation, the naming of Financing
Parties as mortgagees, additional insureds and loss payees, as appropriate, on
each insurance policy obtained pursuant to this clause (a) and (iii) provide an
insurer's waiver of subrogation in favor of each insured party thereunder.

          (b)  The Coker Company shall reimburse Clark R&M for its share of
costs associated with insurance coverage obtained pursuant to clause (a) above
according to the pricing formulas set forth in Schedule 5.13.

          Section 5.14  Licensing, Permits and Approvals.
                        --------------------------------

          (a)  Clark R&M shall investigate, determine, procure, pay for and
maintain in effect, including all renewals and updating thereof, any and all
professional licenses, other Permits, or governmental approvals necessary for
continuous operation of the Heavy Oil Processing Facility including, without
limitation, those listed on Schedule 5.14.

          (b)  To the extent that any Permits are necessary for the continuous
operation of the Coker Complex, Clark R&M shall, to the extent permitted by
Applicable Law, (i) procure such Permits in the Coker Company's name or (ii)
ensure that such Permits are freely assignable by Clark R&M to the Coker Company
and, subsequently, to the Financing Parties. With respect to any Permits
currently held by Clark R&M that are necessary for the continuous operation of
<PAGE>

                                                                              17

the Coker Complex that are not assignable under Applicable Law, Clark R&M agrees
to use its best efforts to ensure that such Permits are procured in the Coker
Company's name.

          (c)  The Coker Company shall reimburse Clark R&M for its share of
costs associated with any licenses, Permits or approvals obtained pursuant to
clause (a) above in accordance with the pricing formula set forth in Schedule
5.14.

          (d)  The Coker Company hereby agrees not to exercise its right,
pursuant to its air emissions permit No. 6825Z and PSD-TX-492 issued by the
Texas Natural Resource Conservation Commission (the "Standby Permit"), to
activate the Standby Permit to cover the entire Refinery, including the
Ancillary Equipment, unless activating the Standby Permit is required to allow
the Coker Company to continue operation of the Coker Complex.  If the Coker
Company activates the Standby Permit, the Coker Company shall cooperate with
Clark R&M, at Clark R&M's sole cost and expense, to modify the Standby Permit to
the extent necessary to obtain air emission permits for the Clark Equipment;

provided that no such modification shall impair or restrict the right of the
--------
Coker Company to operate the Heavy Oil Processing Facility at the greater of its
design capacity or its then actual capacity.

          Section 5.15  Sulfur Recovery Services.
                        ------------------------

          (a)  To the extent, at any time, the Sulfur Plant is unable to process
sulfur produced by the processing of Coker Company-owned feedstreams through the
Ancillary Equipment, the Hydrocracker and the Coker, Clark R&M shall provide the
Coker Company with alternative sulfur recovery services.

          (b)  In exchange for the provision of sulfur recovery services by
Clark R&M pursuant to clause (a) of this Section 5.15, to the extent, at any
time, the Clark R&M-owned sulfur recovery units at the Refinery are unable to
process sulfur produced by the processing of the Clark R&M-owned feedstreams at
the Refinery, the Coker Company agrees to the processing of Clark R&M-owned
sulfur through the Sulfur Plant to the extent that capacity is available at the
Sulfur Plant.

          (c)  Clark R&M shall coordinate the sulfur recovery activities
described in this Section 5.15.

     ARTICLE 6.  ANNUAL BUDGET AND OPERATING PLAN; REPORTING

          Section 6.1  Annual Budget and Operating Plan.
                       --------------------------------

          (a)  The Annual Budget and Operating Plan for the first Operating Year
shall be the budget attached hereto as Schedule 6.1, as the same may be amended
by mutual consent, subject to any approval rights of the Financing Parties or
Independent Engineer set forth in the Financing Documents.

<PAGE>

                                                                              18

          (b)  Sixty (60) calendar days prior to the start of each Operating
Year, other than the first Operating Year, Clark R&M shall prepare and submit to
the Coker Company, the Financing Parties and the Independent Engineer, for their
review and comment, a proposed annual budget and operating plan for such year
which Annual Budget and Operating Plan shall be substantially in the form of
Schedule 6.1 and include, without limitation, (i) detailed line items of the
anticipated revenues and expenses relating to the operation of the Heavy Oil
Processing Facility for such year and (ii) the scheduled maintenance shutdown(s)
of units comprising the Heavy Oil Processing Facility during such year.

          (c)  Subject to any approval rights of the Financing Parties or
Independent Engineer set forth in the Financing Documents, the Coker Company
shall accept or object to all or any portion of the proposed Annual Budget and
Operating Plan within thirty (30) calendar days of receipt thereof. If the Coker
Company objects to any portion of such proposed Annual Budget and Operating
Plan, the Coker Company and Clark R&M shall attempt in good faith to agree to an
Annual Budget and Operating Plan. If the Coker Company and Clark R&M have not
reached agreement on the Annual Budget and Operating Plan for any Operating Year
prior to the first day of such Operating Year, the Annual Budget and Operating
Plan in effect for such Operating Year shall be the same as the Annual Budget
and Operating Plan for the immediately preceding calendar year (with each item
on the budget adjusted based on a percentage change in the U.S. Consumer Price
Index, in each case, from the date the Annual Budget and Operating Plan then in
effect was approved) until a new Annual Budget and Operating Plan is approved.

          Section 6.2  Operating Adjustments.
                       ---------------------

          (a)  Clark R&M may modify the operations of the Ancillary Equipment or
the Coker Complex at its discretion so long as such modification does not (i) in
any way impede production of the Required Product Mix, (ii) cause an increase in
the reimbursable costs of the Coker Company that are payable hereunder that is
not offset by a corresponding increase in revenues under the Product Purchase
Agreement, (iii) adversely affect the reliability of or the useful life of
either the Coker Complex or the Ancillary Equipment, or (iv) otherwise have a
material adverse effect on the Coker Company, the Coker Complex, the Ancillary
Equipment or the Refinery (including, without limitation, a material adverse
effect on the ability of the Coker Company to pay its Senior Debt Obligations
when they become due and payable or to prepay Senior Debt in accordance with the
Base Case Financial Model).

          (b)  The Coker Company and Clark R&M agree to modify the Schedules
when and to the extent necessary in connection with adjustments permitted by
this Section 6.2. In the event of any such adjustments, Clark R&M shall notify
the Coker Company as soon as reasonably possible, and the parties shall
cooperate to effect the intent of this Section.

          (c)  To the extent Clark R&M determines, in its reasonable business
judgment and in conformity with Prudent Industry Practices, that it is
economically and technically prudent to process Coker Company feedstreams
through another Clark R&M processing unit at the Refinery which has
substantially the same processing capabilities as a unit comprising the Heavy
Oil Processing Facility, Clark R&M may substitute the processing capacity of
such unit with the
<PAGE>

                                                                              19

other Clark R&M unit so long as (i) a substantially equivalent volume of Clark
R&M feedstreams are processed through the unit comprising the Ancillary
Equipment, (ii) the Clark Processing Fees shall be calculated as if the Coker
Company feedstreams were processed through the Heavy Oil Processing Facility
unit, and (iii)Clark R&M believes in its reasonable good faith judgment that the
result of such exchange of processing capacities will be to maximize the
profitability of the Refinery as a whole in a manner (A) that is mutually
beneficial to Clark R&M and the Coker Company and (B) that does not maximize the
profitability of Clark R&M at the expense of the Coker Company.

          (d)  To the extent that operational difficulties cause Actual Crude
Capacity for any day to be less than Crude Design Capacity, Clark R&M shall use
commercially reasonable efforts to procure alternative Coker feedstocks on
behalf of itself and the Coker Company in order operate the Coker at Actual
Coker Capacity and preserve the relative processing capacities of Clark R&M and
the Coker Company as would exist if the Ancillary Equipment were operating at
Crude Design Capacity.  In such event, the Coker Company shall reimburse Clark
R&M for all Permitted Reimbursable Expenses incurred by Clark R&M in procuring
such feedstocks on behalf of the Coker Company and the Excess Coker Capacity for
such day shall be deemed to equal the volume necessary to preserve the relative
processing capacities of Clark R&M and the Coker Company as would exist if the
Ancillary Equipment were operating at Crude Design Capacity.

          To the extent that such operating difficulties involve the Crude Unit,
Clark R&M shall use commercially reasonable efforts to procure alternative
feedstocks for the other units comprising the Ancillary Equipment on behalf of
itself and the Coker Company in order operate such units at their actual
capacities and preserve the relative processing capacities of Clark R&M and the
Coker Company as would exist if the Crude Unit were operating at Crude Design
Capacity.  In such event, the Coker Company shall reimburse Clark R&M for all
Permitted Reimbursable Expenses incurred by Clark R&M in procuring such
feedstocks on behalf of the Coker Company and the capacity of such units
available for processing Clark R&M feedstreams pursuant to Section 3.5 hereof
for such day shall be deemed to equal the volume necessary to preserve the
relative processing capacities of Clark R&M and the Coker Company as would exist
if the Crude Unit were operating at Crude Design Capacity.

          Section 6.3  Quarterly Reports.  Clark R&M shall, within forty five
                       -----------------
(45) calendar days after the end of each of the first three calendar quarters of
each year and within ninety (90) days after the end of each calendar year,
submit a report to the Coker Company, the Financing Parties and the Independent
Engineer summarizing the actual operating activities at the Heavy Oil Processing
Facility during that quarter or year, as the case may be, including, without
limitation, the feedstream mixes and volumes utilized and such other operation
information as may be reasonably requested by the Coker Company the Financing
Parties or the Independent Engineer.
<PAGE>

                                                                              20

                        ARTICLE 7.  PRICING AND PAYMENT

          Section 7.1  Pricing of Services and Supplies.
                       --------------------------------

          (a)  The Coker Company shall pay Clark R&M the Applicable Price for
each Service and Supply provided by Clark R&M to the Coker Company hereunder
(except for potable water and sanitary sewage services as provided in Sections
5.5 and 5.6, respectively).

          (b)  Clark R&M shall pay the Coker Company the Clark Processing Fee
for the processing services provided by the Coker Company to Clark R&M
hereunder.

          Section 7.2  Net Pricing and Statements.
                       --------------------------

          (a)  Clark R&M shall deliver to the Coker Company an itemized
statement substantially in the form of Exhibit A hereto (the "Reconciliation
                                                              --------------
Statement") showing computation of the following for the prior monthly period:
---------

               (i)   a calculation of the Applicable Price for each Service and
          Supply provided by Clark R&M to the Coker Company during such period;

               (ii)  a calculation of the Clark Processing Fee for such period;
          and

               (iii) the difference obtained as a result of subtracting the
          amount in 7.2(a)(i) from the amount in 7.2(a) (ii), as such difference
          may be adjusted from time to time pursuant to clause (d) Section 5.11.

          (b)  The Reconciliation Statement shall be considered an invoice to
the Coker Company of the amount computed in clause (a)(iii) above which shall be
paid in accordance with Section 7.3.

          Section 7.3  Payment Procedure.  Payments due under this Article 7
                       -----------------
shall be made pursuant to Reconciliation Statements to be rendered by Clark R&M
to the Coker Company on the eleventh (11/th/) Business Day of each month and to
be paid on the twentieth (20/th/) calendar day of each month.

          Section 7.4  Alternative Pricing.
                       -------------------

          (a)  If a change in Applicable Law requires Clark R&M to make capital
expenditures or change its operating procedures in a manner that directly
results in a material increase in the cost of providing the Services and
Supplies hereunder, then upon the written request of Clark R&M the parties shall
meet to negotiate in good faith an equitable adjustment or adjustments to the
pricing of Services and Supplies hereunder (or an adjustment to the rents
payable under the Coker Complex Ground Lease and/or the Ancillary Equipment Site
Lease, respectively, with respect to the provision of potable water or sanitary
sewage service); provided, however, that no such adjustment or adjustments shall
                 --------  -------
become effective unless or until Clark
<PAGE>

                                                                              21

R&M has demonstrated to the satisfaction of the Coker Company (and such other
parties as required under the Financing Documents) that such adjustment or
adjustments shall not (i) have a material adverse effect on the ability of the
Coker Company to pay its Senior Debt Obligations when they become due or payable
and (ii) become effective until approved by the Independent Engineer.

          (b)  In the event that either party hereto determines in good faith
judgment that the provisions set forth under the heading "Applicable Price" on
the Schedule relating to any Service or Supply hereunder does not accurately
reflect the actual cost of providing such Service or Supply (for any reason
other than a change in Applicable Law), then upon written request of such party
the parties shall meet to negotiate in good faith an equitable adjustment or
adjustments to the pricing of such Services or Supply to reflect the actual cost
of providing such Service or Supply (and to preserve the profit component, if
any, of such price); provided, however, that such adjustment or adjustments
                     --------  -------
shall not (i) have a material adverse effect on the ability of the Coker Company
to pay its Senior Debt Obligations when they become due or payable and (ii)
become effective until approved by the Independent Engineer.

          (c)  To the extent that any expansion of operations of Clark R&M at
the Refinery (including, without limitation, the operation of the existing Clark
R&M cokers after the Start-up Date) causes the Applicable Price of any Service
to be provided pursuant to Sections 5.5 or 5.6 to increase, Clark R&M shall
reduce the amounts charged the Coker Company for such Service so that the
Applicable Price of such Service shall conform to the pricing that would have
been in effect if such expansion had not occurred.

          (d)  Any disputes with respect to the foregoing shall be resolved in
accordance with Section 11.6 below.

          Section 7.5  Recordkeeping; Right to Audit; Access to Books and
                       --------------------------------------------------
                       Records.
                       -------

          (a)  Clark R&M shall, in accordance with good business practices, keep
and maintain such books, records, accounts and other documents as may be
necessary to the performance of its obligations hereunder and which are
sufficient to reflect accurately and completely all amounts which form the basis
for Reconciliations Statements. Such records shall include receipts, memoranda,
vouchers, inventories, and accounts of every kind and nature pertaining to the
accounting for the Services and Supplies, as well as complete summaries and
reports setting forth in reasonably detail all reimbursable expenses incurred.

          (b)  The Coker Company shall have the right to audit all costs
incurred by Clark R&M for which Clark R&M seeks payment hereunder and shall have
the right to inspect and examine, during regular business hours and on not less
than five (5) days notice to Clark R&M all records maintained pursuant to clause
(a) above.

          Section 7.6  Interest Rate for Late Payments.  All amounts payable
                       -------------------------------
hereunder if not paid when due will accrue interest daily at the annual rate of
interest announced from time to time for dollars by The Chase Manhattan Bank,
N.A. at its offices located in New York, New
<PAGE>

                                                                              22

York as its prime commercial interest rate for U.S. Dollar-denominated loans
originated in the United States plus two percent (2%) calculated from the due
date of such payment until the date of payment.

                 ARTICLE 8. DEFAULTS, REMEDIES AND TERMINATION

          Section 8.1  Clark R&M's Right to Terminate.  The failure of the Coker
                       ------------------------------
Company to pay any amount due hereunder in excess of $250,000 which remains
uncured for a period of five (5) consecutive days from the date when payment of
such amount is due shall constitute a Coker Company default hereunder.

          If a Coker Company default shall occur and be continuing, Clark R&M
after having given the Coker Company and the Financing Parties ninety (90) days
prior written notice may terminate this Services and Supply Agreement upon the
Coker Company's and/or the Financing Parties' subsequent failure to cure such
default within such ninety (90) day cure period.

          Section 8.2  Coker Company's Right to Terminate and Other Remedies.
                       -----------------------------------------------------
Each of the following shall constitute a Clark R&M default hereunder:

          (a)  Failure by Clark R&M to pay any amount due hereunder in excess of
$250,000 on the date when payment of such amount is required, which continues
uncured for a period of five (5) consecutive days;

          (b)  Failure by Clark R&M to perform substantially any material
obligation hereunder, which failure continues uncured for a period of thirty
(30) consecutive days;

          (c)  Commencement of insolvency, receivership, reorganization or
bankruptcy proceedings by or against Clark R&M, which are not dismissed within
60 days;

          (d)  Any material representation or warranty of Clark R&M herein that
continues uncured for a period of sixty (60) consecutive days;

          (e)  Default by Clark R&M under Section 6.2 to the Product Purchase
Agreement; and

          (f)  Failure by Clark R&M to perform substantially any material
obligation under the Ancillary Equipment Site Lease or the Coker Complex Ground
Lease, which failure continues uncured for a period of thirty (30) consecutive
days.

          Upon the occurrence of a Clark R&M default hereunder and subject to
such consent as may be required under the Financing Documents, the Coker Company
may take any of the following actions, provided that with respect to a default
                                       --------
pursuant to clause (a) or (b) of this Section 8.2, the Coker Company shall have
first given Clark R&M sixty (60) days notice and
<PAGE>

                                                                              23

opportunity to cure such default and Clark R&M shall have failed to cure such
default in its entirety within such sixty (60) day cure period:  (x) terminate
this Services and Supply Agreement, and/or (y) exercise any or all remedies
available to it at law or in equity.

          Section 8.3  Termination Option.  Notwithstanding anything to the
                       ------------------
contrary herein and subject to such consent as may be required under the
Financing Documents, this Services and Supply Agreement shall terminate at the
option of either party hereto should Final Completion (as such term is defined
in the EPC Contract) and completion of the Lessor Ancillary Equipment Upgrade
not occur on or before March 1, 2002 or such later date for completion of
construction of the Heavy Oil Processing Facility as may be contemplated by the
Financing Documents.

          Section 8.4  Non-Exclusive Remedies; Specific Performance.
                       --------------------------------------------

          (a)  None of the provisions in this Article 8 are intended to be
exclusive of, or to limit, any rights available to either party at law or in
equity.

          (b)  Each of the parties hereto acknowledges and agrees that (i)
monetary damages may be an inadequate remedy for a breach of any of the
provisions of this Services and Supply Agreement, (ii) in addition to being
entitled to exercise all of its rights granted by law, including recovery of
damages, the other party shall therefore be entitled to specific performance of
the other party's obligations under this Services and Supply Agreement and (iii)
in the event of any action for specific performance it shall waive the defense
that a remedy at law would be adequate.

                ARTICLE 9.  TERM, AND COMMENCEMENT OF SERVICES

          Section 9.1  Effectiveness; Term.  This Services and Supply Agreement
                       -------------------
shall become effective on the date hereof and shall continue in effect until the
earlier of (a) the date on which this Services and Supply Agreement is
terminated pursuant to Article 8, and (b) the date of that is thirty (30) years
after the date hereof.

          Section 9.2  End of Term Obligations.
                       -----------------------

          Upon the expiration or termination, for whatever reason, of this
Services and Supply Agreement:

          (a)  Clark R&M shall cooperate with the Coker Company to enable it to
continue operation of the Coker Complex, reclaim goods, equipment and materials,
and otherwise effectuate the smooth transition of operations of the Coker
Complex to the Coker Company or a new manager engaged by the Coker Company;

          (b)  The Coker Company shall have the right, in its sole discretion,
directly to assume and become liable for any contracts or obligations that Clark
R&M may have undertaken
<PAGE>

                                                                              24

with third parties in connection with the Services or provision of the Supplies
(other than any contracts or obligations related to the provision of electric
utilities or electric service), and Clark R&M shall execute all documents and
take all other reasonable steps requested by the Coker Company which may be
required to assign to and vest in the Coker Company all rights, benefits,
interest and title in connection with such contracts or obligations;

          (c)  Clark R&M shall deliver to the Coker Company all materials and
documents that are the Coker Company property including, without limitation, the
property referred to in Section 11.8; and

          (d)  Clark R&M and the Coker Company shall cooperate to amend their
respective Permits to reallocate their respective rights thereunder as necessary
for the Coker Company to continue operation the Heavy Oil Processing Facility
and Clark R&M to continue operation of the Clark Equipment.

                  ARTICLE 10. REPRESENTATIONS AND WARRANTIES

          Section 10.1  Representations and Warranties of the Coker Company.
                        ---------------------------------------------------

          The Coker Company represents and warrants to Clark R&M that:

          (a)  The Coker Company is a limited partnership duly formed and
validly existing under the laws of the State of Delaware; the Coker Company has
the power and authority to own its assets and to transact the business in which
it is now engaged or proposed to be engaged in; and the Coker Company is duly
qualified to do business in each jurisdiction in which the character of the
properties owned by it therein or in which the transaction of its business makes
such qualification necessary.

          (b)  The execution, delivery and performance by the Coker Company of
this Services and Supply Agreement has been duly authorized by all necessary
corporate action and does not and will not: (1) require any further consent or
approval of the members of the Coker Company; (2) contravene the Coker Company's
partnership agreement or limited partnership certificate; (3) violate any
provision of any law, rule, regulation, order, writ, judgment, decree,
determination, or award presently in effect having applicability to the Coker
Company; (4) result in a breach of or constitute a default under any indenture
or loan or credit agreement or any other agreement, lease or instrument to which
the Coker Company is a party or by which it or its properties may be bound or
affected; (5) result in, or require, the creation or imposition of any lien,
upon or with respect to any of the properties now owned or hereafter acquired by
the Coker Company; or (6) cause the Coker Company to be in default under any
such law, rule, regulation, order, writ, judgment, injunction, decree,
determination, or award or any such indenture, agreement, lease or instrument.

          (c)  This Services and Supply Agreement is in full force and effect
and is the legal, valid, and binding obligation of the Coker Company,
enforceable against the Coker
<PAGE>

                                                                              25

Company in accordance with its terms, except to the extent that such enforcement
may be limited by applicable bankruptcy, moratorium, insolvency or other similar
laws affecting creditors' rights generally and by general equitable principles
(whether enforcement is sought by proceedings in equity or at law).

          Section 10.2  Representations and Warranties of Clark R&M.
                        -------------------------------------------

          Clark R&M represents and warrants to the Coker Company that:

          (a)  Clark R&M is a corporation duly formed and validly existing under
the laws of Delaware; Clark R&M has the corporate power and authority to own its
assets and to transact the business in which it is now engaged or proposed to be
engaged in; and Clark R&M is duly qualified to do business in each jurisdiction
in which the character of the properties owned by it therein or in which the
transaction of its business makes such qualification necessary.

          (b)  The execution, delivery and performance by Clark R&M of this
Services and Supply Agreement has been duly authorized by all necessary
corporate action and does not and will not: (1) require any further consent or
approval of the members of Clark R&M; (2) contravene Clark R&M's certificate of
incorporation or by laws, (3) violate any provision of any law, rule,
regulation, order, writ, judgment, decree, determination, or award presently in
effect having applicability to Clark R&M; (4) result in a breach of or
constitute a default under any indenture or loan or credit agreement or any
other agreement, lease or instrument to which Clark R&M is a party or by which
it or its properties may be bound or affected; (5) result in, or require, the
creation or imposition of any lien, upon or with respect to any off the
properties now owned or hereafter acquired by Clark R&M; or (6) cause Clark R&M
to be in default under any such law, rule, regulation, order, writ, judgment,
injunction, decree, determination, or award or any such indenture, agreement,
lease or instrument.

          (c)  This Services and Supply Agreement is in full force and effect
and is the legal, valid, and binding obligation of Clark R&M enforceable against
Clark R&M in accordance with its terms, except to the extent that such
enforcement may be limited by applicable bankruptcy, moratorium, insolvency, or
other similar laws affecting creditors' rights generally and by general
equitable principles (whether enforcement is sought by proceedings in equity or
at law).

          (d)  Clark R&M has all the required skills and capacity necessary to
provide and shall diligently provide the Services and Supplies in a timely and
professional manner, utilizing sound operation principles, project management
procedures and supervisory procedures, all in accordance with Applicable Law,
Prudent Industry Practice and the Base Case Financial Model.
<PAGE>

                                                                              26

                        ARTICLE 11. FURTHER AGREEMENTS

          Section 11.1  Intellectual Property; Confidentiality. Clark R&M agrees
                        --------------------------------------
to be bound by all confidentiality agreements and all agreements with respect to
intellectual property rights contained in the other Project Documents.

          Section 11.2  Force Majeure.
                        -------------

          (a)  If an Event of Force Majeure causes a material adverse effect on
a party's ability to carry out its obligations hereunder, other than the
obligation to pay money, such party shall give to the other party prompt notice
of such Event of Force Majeure with reasonably full particulars thereof, and any
such obligations so far as they are affected by such Event of Force Majeure
shall be suspended during but not longer than the continuance of such Event of
Force Majeure and such further period thereafter as shall be reasonable in the
circumstances.

          (b)  As soon as practicable after giving notice under clause (a) above
the claiming party shall provide to the other party confirmation of the
particulars required to be given under clause (a) above.

          (c)  Nothing in this Section 11.2 shall suspend, excuse or delay any
party's obligation to pay hereunder.

          (d)  The non-performing party shall use reasonable diligence to remedy
its inability to perform or to minimize the impact of the Event of Force Majeure
as quickly as possible.

          Section 11.3  Cooperation with Other Parties. Clark R&M shall
                        ------------------------------
reasonably cooperate with the Coker Company, the Independent Engineer and the
Financing Parties in connection with the Financing Documents and/or any
refinancing thereof including, without limitation, the furnishing of such
information, the giving of such certificates and the furnishing of a reasonable
consent and such reasonable opinions of counsel and other matters as the Coker
Company, the Independent Engineer or the Financing Parties may reasonably
request in connection with the transactions contemplated hereby or by the
Financing Documents.

          Section 11.4  Site Access. The Coker Company hereby grants to Clark
                        -----------
R&M a continuing license to use the portions of the Refinery owned or leased by
the Coker Company (the "Coker Company Site") to the extent necessary to perform
                        ------------------
its obligations hereunder.

          Section 11.5  Indemnity.
                        ---------

          (a)  The Coker Company shall protect, indemnify, defend and hold
harmless Clark R&M, and Clark R&M shall protect, indemnify, defend and hold
harmless the Coker Company and the Financing Parties, together with in each case
the respective indemnitee's directors, officers, employees and agents (including
but not limited to affiliates and their employees) from and against all
liabilities, damages, losses, penalties, claims, judgments,
<PAGE>

                                                                              27

awards, costs, expenses (including reasonable legal fees and any fines or
assessments charged against it), demands, suits and proceedings of any nature
whatsoever for death, injury or property damage that arise out of or are in any
manner connected with the negligence or willful misconduct of that party in its
performance of this Services and Supply Agreement.

          (b)  Each party's obligations with respect to claims and suits covered
by this Section are subject to the conditions that (i) the indemnitee gives the
indemnitor reasonably prompt notice of any such claim or suit, (ii) the
indemnitee cooperates in the defense of any such claim or suit and (iii) the
indemnitor has sole control of the defense and settlement to the extent of the
indemnitor's liability for any such claim or suit, provided that indemnitor
                                                   --------
shall confirm in writing its obligation to indemnify the indemnitee with respect
to all costs and expenses with respect to such claim or suit.  Nothing contained
in this clause (b), however, shall preclude the indemnitee from (x) being
represented by its own counsel at its own expense or (y) participating in the
settlement if the claimed relief is non-monetary in nature.

          (c)  The Coker Company hereby agrees that, notwithstanding any
provision herein to the contrary, with respect to any loss that is or would be
covered by the policies of insurance specified in Section 5.13, Clark R&M shall
first seek to recover insurance proceeds under such policies, through submission
of a claim and exercise of good faith efforts over the ensuing sixty (60) day
period toward recovery of damages hereunder.

          Section 11.6  Dispute Resolution.
                        ------------------

          (a)  In the event of any dispute arising out of or in connection with
the Services and Supply Agreement, Clark R&M or the Coker Company may notify the
other party of the nature of the dispute and the parties shall, in good faith
and using all reasonable efforts, seek to settle the dispute amicably through
negotiation between senior executives. Within twenty (20) days after delivery of
such notice, such senior executives shall meet at a mutually acceptable time and
place, and thereafter as often as reasonably deemed necessary, to exchange
relevant information and to attempt to resolve the dispute. All discussions
pursuant to this clause (a) shall be confidential and shall be treated as
compromise and settlement negotiations for all purposes including the admission
of evidence in any subsequent arbitration. If the matter has not been resolved
within sixty (60) days of the delivery of notice of the dispute, or if the
parties fail to meet within the twenty-day period referred to above, either
party may initiate arbitration of the dispute pursuant to the terms of clause
(b) of this Section.

          (b)  All disputes arising out of or in connection with the Services
and Supply Agreement shall be settled finally by arbitration under rules
applicable to arbitrations of the American Arbitration Association (the "AAA
                                                                         ---
Rules") in effect at such time. The arbitration shall take place in New York
-----
City. Subject to the provisions of paragraph (c) below, the arbitral tribunal
shall consist of three arbitrators, one designated by each of the parties and
the third, who shall be the chairman of the tribunal, selected by agreement of
the two designated arbitrators. In the event the two arbitrators fail to agree
on the selection of the chairman, the chairman shall be selected in accordance
with ABB Rules. The substantive law applicable to the subject matter of the
arbitration shall be the law indicated in Section 12.8. Copies of the request
for arbitration
<PAGE>

                                                                              28

and the answer thereto shall be served by a party on the other party in
accordance with Section 12.7. Subject to paragraph (c) below, the award of the
arbitral tribunal shall be rendered within one hundred eighty (180) days from
signature or approval of the terms of reference, subject to extension for good
cause only. The award shall be final and binding on the parties, and may be
confirmed or embodied in any order or judgment of any court of competent
jurisdiction.

          (c)  In the case of any claim for damages in a principal amount of two
hundred fifty thousand U.S. dollars (U.S.$250,000) or less, (i) the claim shall
be resolved by a sole arbitrator selected in accordance with AAA Rules, (ii) the
terms of reference shall be signed and any hearing of the matter shall be held
within one hundred twenty (120) days following the later of service of the
answer and transmission of the file to the arbitrator, and (iii) the arbitrator
shall render the award within thirty (30) days after the hearing or, in the
event a hearing is not held, signature or approval of the terms of reference,
subject extension for good cause only.

          Section 11.7  Taxes.
                        -----

          (a)  The Coker Company shall be responsible for payment of or
reimbursement of the cost to Clark R&M of (i) all duties and all real property,
personal property, sales, use, municipal or VAT, and other like taxes, in each
case assessed against the Coker Complex and (ii) its pro rata share of all
duties and all real property, personal property, sales, use, municipal or VAT,
and other like taxes, in each case assessed against the Ancillary Equipment.

          (b)  Clark R&M shall use commercially reasonable efforts to minimize
the tax obligations arising out of or associated with this Services and Supply
Agreement, the Ancillary Equipment or the Coker Complex and shall assist the
Coker Company in (i) applying for available tax exemptions including, without
limitation, a Texas direct pay permit and (ii) preparing and submitting any
exemption certificates required under the clause (a) above. When obtained, the
Coker Company shall issue Clark R&M its Texas direct pay permit for the
provisions of Services and Supplies hereunder. If, for any reason, during the
term of this Services and Supply Agreement, the Coker Company provides Clark R&M
products or services which are subject to Texas sales and use tax, Clark R&M
shall provide it Texas direct pay permit to the Coker Company.

          (c)  Each party shall be solely responsible for payment of any
federal, state or local taxes based on upon or measured by such party's income.

          Section 11.8  Title to Property.
                        -----------------

          (a)  Title to all materials, equipment, supplies, consumables, spare
parts and other items purchased or obtained by Clark R&M in connection with
performance of the Services related to, and provision of the Supplies for, the
Coker Complex shall pass immediately to and vest in the Coker Company upon
passage of title from the vendor or supplier thereof.

          (b)  All materials and documents prepared or developed by Clark R&M or
its employees, representatives or contractors in connection with performance of
the Services related
<PAGE>

                                                                              29

to, and provision of Supplies for, the Coker Complex, including all manuals,
data, designs, drawings, plans, specifications, reports, and accounts shall
become the property of the Coker Company when prepared, and Clark R&M and its
contractors.

          Section 11.9  Subcontractors.
                        --------------

          (a)  Clark R&M shall have the right to subcontract any portion of the
Services to be provided hereunder and enter into supply agreements with third
parties in connection with the provision of Supplies hereunder.  Clark R&M shall
assure that its subcontractors, subcontracts and supply agreements comply with
all pertinent provisions of this Services and Supply Agreement.

          (b)  Clark R&M shall remain responsible for all of its obligations
under this Supply and Service Agreement regardless of whether a subcontract or
supply agreement is made or whether Clark R&M relies upon any subcontractor to
any extent.  Clark R&M's use of subcontractors for the performance of its
obligations hereunder shall in no way increase Clark R&M's rights or diminish
Clark R&M's liabilities hereunder with respect to the Coker Company and this
Services and Supply Agreement shall be as though Clark R&M had itself performed
such obligations.

          (c)  The Coker Company shall not be deemed by virtue of any
subcontract entered into by Clark R&M in connection herewith to have any
contractual obligation to or relationship with any subcontractor of Clark R&M.

                           ARTICLE 12. MISCELLANEOUS

          Section 12.1  Relationship of Parties.
                        -----------------------

          (a)  Nothing in this Services and Supply Agreement shall be deemed to
constitute either party hereto a partner, joint venturer, agent or legal
representative of the other party or to create any fiduciary relationship
between or among the parties.

          (b)  Clark R&M shall at all times be deemed an independent contractor
with respect to the provision of Services and Supplies and neither it nor any of
its employees or the employees of any of its subcontractors shall be considered
an agent, servant or employee of the Coker Company.

          Section 12.2  Third Party Beneficiaries.  (a) The Financing Parties
                        -------------------------
are intended third party beneficiaries of this Services and Supply Agreement and
the representations, warranties, covenants and agreements of the parties hereto
are made for the benefit of, and may be relied upon by, the Financing Parties.
<PAGE>

                                                                              30

          (b)  Except as otherwise provide in this Section 12.2, the rights and
obligations created hereunder shall apply exclusively to the parties hereto and
their successors and permitted assigns, and no right shall be created in any
third party by reason of this Services and Supply Agreement or separate act or
action taken independently by either party.

          Section 12.3  Clark R&M Warranties.
                        --------------------

          (a)  Clark R&M warrants that at time of delivery, each product that
Clark R&M supplies to the Coker Company hereunder shall meet its respective
specifications set forth herein and in the Schedule in all material respects.
CLARK R&M DOES NOT MAKE, AND EXPRESSLY DISCLAIMS, ANY OTHER WARRANTIES
WHATSOEVER WITH RESPECT TO THE PRODUCTS TO BE SUPPLIED BY CLARK R&M HEREUNDER,
INCLUDING WITHOUT LIMITATION ANY WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A
PARTICULAR PURPOSE.

          (b)  Clark R&M hereby assigns any assignable warranties made by third
party suppliers for any products supplied by it hereunder. Clark R&M shall
cooperate with the Coker Company in claims made by the Coker Company against any
third party suppliers regardless of any warranty rights. The Coker Company
hereby releases Clark R&M from claims arising from a breach of such third party
warranties.

          (c)  Clark R&M warrants that each Service or Supply provided by Clark
R&M to the Coker Company hereunder shall meet its respective specifications set
forth herein and in the Schedules in all material respects and shall meet the
practices Clark R&M generally uses to perform similar functions at other United
States refinery facilities it owns and operates. CLARK R&M DOES NOT MAKE, AND
EXPRESSLY DISCLAIMS, ANY OTHER WARRANTIES WHATSOEVER WITH RESPECT TO THE
SERVICES AND SUPPLIES TO BE PROVIDED BY CLARK R&M HEREUNDER, INCLUDING WITHOUT
LIMITATION ANY WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR
PURPOSE.

          Section 12.4  No Indirect Damages. Notwithstanding anything to the
                        -------------------
contrary herein, in no event shall either party be liable for consequential,
incidental, indirect, special or punitive damages hereunder including, without
limitation, any damages measured by the principal amount of the Coker Company's
obligations under the Financing Documents.

          Section 12.5  Assignments.
                        -----------

          (a)  Clark R&M shall not assign its rights hereunder without the prior
written consent of the Coker Company and the Financing Parties.  The Coker
Company may assign its rights hereunder to the Financing Parties, as collateral
security for its obligations under the Financing Documents, but otherwise shall
not assign its rights hereunder without the prior written consent of Clark R&M
and the Financing Parties. Clark R&M hereby expressly authorizes the Financing
Parties, or the Collateral Trustee acting on behalf of the Financing Parties, as
a secured party, to exercise all rights of the Coker Company under this Services
and Supply Agreement and to subsequently assign such rights in connection
therewith.
<PAGE>

                                                                              31

          (b)  This Services and Supply Agreement shall be binding upon and
shall inure to the benefit of, the successors and permitted assigns of Clark R&M
and the Coker Company.

          (c)  This Services and Supply Agreement shall inure to the benefit of
the Collateral Trustee, the Financing Parties and any subsequent transferee or
assignee thereof.

          (d)  Notwithstanding anything to the contrary herein, no assignment of
the rights of the Coker Company with respect to the Regulated Utilities to any
Person shall be effective unless and until the rights of the Coker Company under
the Coker Complex Ground Lease and the Ancillary Equipment Site Lease are
assigned to such Person.

          Section 12.6  Amendments.  No amendment, modification or alteration of
                        ----------
the terms hereof shall be binding unless the same is in writing and duly
executed by each of the parties hereto.

          Section 12.7  Notices.  Any notice, request, consent, waiver or other
                        -------
communication required or permitted hereunder shall be effective only if it is
in writing and personally delivered by hand or by overnight courier or sent by
certified or registered mail, postage prepaid, return receipt requested,
addressed as follows:

          If to Clark R&M:

               Clark Refining & Marketing, Inc.
               8182 Maryland Avenue
               St. Louis, Missouri 63105
               Attention: Richard A. Keffer

          If to the Coker Company:

               Port Arthur Coker Company L.P.
               Port Arthur Refinery
               1801 S. Gulfway Drive
               Office Number 36
               Port Arthur, Texas 77640
               Attention: K.W. Isom

               (or if sent by U.S. Mail:

               Port Arthur Coker Company L.P.
               P.O. Box 908
               Port Arthur, Texas 77641-0908
               Attention: K.W. Isom)
<PAGE>

                                                                              32

          Any such notice, request, consent, waiver or other communication
required or permitted hereunder, whether to Clark R&M or the Coker Company,
shall also be personally delivered by hand or by overnight courier or sent by
certified or registered mail, postage prepaid, return receipt requested, to the
Collateral Trustee on behalf of the Financing Parties, addressed as follows:

               Bankers Trust Company
               Corporate Trust & Agency Services
               Four Albany Street, 4/th/ Floor
               New York, New York 10006
               Attention: James McDonough

          Section 12.8  GOVERNING LAW.  THE PLACE OF EXECUTION, DELIVERY OR
                        -------------
PERFORMANCE OF THIS SERVICES AND SUPPLY AGREEMENT OR OF THE DOMICILE OF THE
PARTIES HERETO NOTWITHSTANDING, THIS SERVICES AND SUPPLY AGREEMENT AND THE
RIGHTS AND OBLIGATIONS OF THE PARTIES UNDER THIS SERVICES AND SUPPLY AGREEMENT
SHALL BE GOVERNED BY, AND CONSTRUED AND INTERPRETED IN ACCORDANCE WITH, THE LAW
OF THE STATE OF NEW YORK; PROVIDED, HOWEVER, THAT MATTERS AFFECTING THE
OBLIGATION OF CLARK R&M TO PROVIDE ELECTRIC UTILITIES OR ELECTRIC SERVICE,
NATURAL GAS OR GAS SERVICE, POTABLE WATER OR WATER SERVICE OR SANITARY SEWAGE
SERVICES TO THE COKER COMPANY, INCLUDING THE ENFORCEMENT OF REMEDIES WITH
RESPECT THERETO, SHALL BE GOVERNED BY, AND CONSTRUED AND INTERPRETED IN
ACCORDANCE WITH, THE LAWS OF THE STATE OF TEXAS.

          Section 12.9  Submission to Jurisdiction; Forum Selection.
                        -------------------------------------------

          (a)  Each of the parties hereto submits to the non-exclusive
jurisdiction of the courts of the State of New York, the State of Texas and the
courts of the United States of America located in the State of New York and the
State of Texas over (i) any suit, action or proceeding with respect to this
Services and Supply Agreement or the transactions contemplated hereby if not
settled by arbitration pursuant to Section 11.6 above and (ii) the enforcement
of any arbitral award issued pursuant to Section 11.6 above.

          (b)  Except for an arbitration award under Section 11.6 hereof, any
suit, action or proceeding with respect to this Services and Supply Agreement or
the transactions contemplated hereby, or the enforcement of any arbitral award
in connection therewith, may be brought only in the courts of the State of New
York or the courts of the United States of America located in the State of New
York, in each case located in the Borough of Manhattan, City of New York, State
of New York. Each of the parties hereto waives any objection that it may have to
the
<PAGE>

                                                                              33

venue of such suit, action or proceeding in any such court or that such suit,
action or proceeding in such court was brought in an inconvenient court and
agrees not to plead or claim the same.

          Section 12.10  Appointment of Agent for Service of Process.  Each
                         -------------------------------------------
party hereto irrevocably appoint CT Corporation, at 1633 Broadway, New York, New
York 10019, as its authorized agent in the State of New York upon which process
may be served in any suit, action or proceeding with respect to this Services
and Supply Agreement or the transactions contemplated hereby, and agrees that
service of process upon such agent, and written notice of said service to such
party by the person serving the same to the address provided in Section 12.7,
shall be deemed in every respect effective service of process upon such party in
any such suit or proceeding. Each party hereto further agrees to take any and
all action as may be necessary to maintain such designation and appointment of
such agent in full force and effect so long as this Services and Supply
Agreement is in effect pursuant to Section 9.1.

          Section 12.11  No Waiver.  The waiver of either party of a default or
                         ---------
breach of any provision of this Services and Supply Agreement by the other party
shall not operate or be construed to operate as a waiver of any subsequent
defaults or breaches of the same or different kind.  The failure of a party to
exercise any rights hereunder in a particular instance shall not operate as a
waiver of such party's right to exercise the same or different rights in
subsequent instances.  The making or acceptance of a payment by either party
with knowledge of the existence of a default or breach shall not operate or be
construed to operate as a waiver of any default or breach.

          Section 12.12  Counterparts.  This Services and Supply Agreement may
                         ------------
be executed by one or more of the parties to this Services and Supply Agreement
on any number of separate counterparts, and all of said counterparts taken
together shall be deemed to constitute one and the same instrument. Delivery of
an executed signature page of this Services and Supply Agreement by facsimile
transmission shall be effective as delivery of a manually executed counterpart
hereof.

          Section 12.13  Integration.  This Services and Supply Agreement and
                         -----------
the other Project Documents represent the agreement of the Coker Company and
Clark R&M with respect to the subject matter hereof, and there are no promises,
undertakings, representations or warranties by the Coker Company or Clark R&M
relative to subject matter hereof not expressly set forth or referred to herein
or in the other Project Documents.

          Section 12.14  Severability.  Any provision of this Services and
                         ------------
Supply Agreement which is prohibited or unenforceable in any jurisdiction shall,
as to such jurisdiction, be ineffective to the extent of such prohibition or
unenforceability without invalidating the remaining provisions hereof, and any
such prohibition or unenforceability in any jurisdiction shall not invalidate or
render unenforceable such provision in any other jurisdiction.

          Section 12.15  Headings.  Captions and headings in this Services and
                         --------
Supply Agreement are for reference only and do not constitute a part of the
substance of this Services and Supply Agreement.
<PAGE>

                                                                              34

          Section 12.6   WAIVER OF JURY TRIAL.   THE COKER COMPANY AND CLARK R&M
                         --------------------
HEREBY IRREVOCABLY AND UNCONDITIONALLY WAIVE TRIAL BY JURY IN ANY LEGAL ACTION
OR PROCEEDING RELATING TO THIS SERVICES AND SUPPLY AGREEMENT OR ANY OTHER
PROJECT DOCUMENT AND FOR ANY COUNTERCLAIM THEREIN.

          IN WITNESS WHEREOF, the parties hereto, intending to be legally bound,
have caused this Services and Supply Agreement to be signed by their respective
officers thereunto duly authorized as of the day and year first set forth above.

                              CLARK REFINING & MARKETING, INC.

                              By: /s/ Maura J. Clark
                                  --------------------------------------
                              Name: Maura J. Clark
                              Title: Executive Vice President and
                                      Chief Financial Officer

                              PORT ARTHUR COKER COMPANY L.P.

                              By:  SABINE RIVER HOLDING CORP., as
                                   General Partner

                                   By: /s/ Maura J. Clark
                                       ---------------------------------
                                   Name: Maura J. Clark
                                   Title: Executive Vice President and
                                           Chief Financial Officer
<PAGE>

                                                  APPENDIX A-DEFINITIONS TO THE:
                                                   Services and Supply Agreement
                                                      Product Purchase Agreement
                                                      Coker Complex Ground Lease
                                                  Ancillary Equipment Site Lease
                                               Transfer and Assignment Agreement

     General Provisions
     ------------------

     The following terms shall have the following meanings for all purposes of
the Services and Supply Agreement, the Product Purchase Agreement, Coker Complex
Ground Lease, the Ancillary Equipment Site Lease and the Transfer and Assignment
Agreement, each referred to below, unless otherwise defined in such agreements
or the context thereof shall otherwise require, and such meanings shall be
equally applicable to both the singular and the plural forms of the terms herein
defined.  In the case of any conflict between the provisions of this Appendix A
and the provisions of the main body of any of the above agreements, the
provisions of the main body of such agreement shall control the construction of
such agreement.

     Unless the context otherwise requires, references to (i) agreements shall
include sections, schedules, exhibits and appendices thereto and shall be deemed
to mean and include such agreement (and sections, schedules, exhibits and
appendices) as the same may be amended, supplemented and otherwise modified from
time to time, (ii) parties to agreements or government agencies shall be deemed
to include the permitted successors and assigns of such parties and the
successors and assigns of such agencies and (iii) laws or regulations shall be
deemed to mean such laws or regulations as the same may be amended from time to
time and any superseding laws or regulations covering the same subject matter.

     "Actual Coker Capacity" means with respect to the Coker, its capacity, from
      ---------------------
time to time, to process feedstreams.

     "Actual Crude Capacity" means with respect to the Ancillary Equipment, its
      ---------------------
capacity, from time to time, to process crude oil.

     "Actual Hydrocracker Capacity" means with respect to the Hydrocracker, its
      ----------------------------
capacity, from time to time, to process gas oil.

     "Adjacent Refinery Property" means the land described on Exhibit B to the
      --------------------------
Coker Complex Ground Lease and also on Exhibit C to the Ancillary Equipment Site
Lease.

     "Amine Treating Unit" means the amine treating unit to be constructed
      -------------------
at the Refinery and designated ATU 7841.

     "Ancillary Equipment" means, collectively, the Crude Unit and the other
      -------------------
processing units described on Exhibit B to the Ancillary Equipment Site Lease.

     "Ancillary Equipment Easement" has the meaning given such term in Section
      ----------------------------
2.2 of the Ancillary Equipment Site Lease.
<PAGE>

                                                                               2

     "Ancillary Equipment Operating Fee" has the meaning given such term in
      ---------------------------------
Section 13.2(b) of the Ancillary Equipment Site Lease.

     "Ancillary Equipment Site" has the meaning given such term in Section 2.1
      ------------------------
of the Ancillary Equipment Site Lease.

     "Ancillary Equipment Site Initial Term" means the period commencing on the
      -------------------------------------
August 19, 1999 and ending on August 19, 2029.

     "Ancillary Equipment Site Lease" means the Ancillary Equipment Site Lease
      ------------------------------
and Easement Agreement, dated as of August 19, 1999, between Clark R&M and the
Coker Company.

     "Ancillary Equipment Site Leasehold" has the meaning given such term in
      ----------------------------------
Section 2.1 of the Ancillary Equipment Site Lease.

     "Ancillary Equipment Site Lease Term" has the meaning given such term in
      -----------------------------------
Article XX of the Ancillary Equipment Site Lease.

     "Ancillary Equipment Site Renewal Term" means each period following the end
      -------------------------------------
of the Ancillary Equipment Initial Term with respect to which Lessee has the
option to renew the Ancillary Equipment Site Lease pursuant to Article XX of the
Ancillary Equipment Site Lease.

     "Ancillary Equipment Upgrade Contract" means the Reimbursable Contract for
      ------------------------------------
Engineering, Procurement and Construction, dated as of March 24, 1998, between
Clark R&M and the Contractor, as amended by Amendment No. One, dated as of
August 19, 1999, as further amended, supplemented or otherwise modified from
time to time.

     "Annual Budget and Operating Plan" means, for any Operating Year, the
      --------------------------------
budget and operating plan in effect pursuant to Section 6 of  the Services and
Supply Agreement.

     "Applicable Law" means, collectively, (i) all Permits and (ii) all laws,
      --------------
treaties, ordinances, judgments, decrees, injunctions, writs, orders and
stipulations of any court, arbitrator or governmental agency or authority and
statutes, rules, regulations, orders and interpretations thereof of any federal,
state, county, municipal, regional, environmental or other governmental body,
instrumentality, agency, authority, court or other body applicable from time to
time to the Refinery, the operation or maintenance of the Refinery, or the
performance of any obligations under the Clark R&M Agreements, any other Project
Document or any other agreement entered into in connection therewith.

     "Appraisal Procedure" with respect to any renewal option of any lease,
      -------------------
means a procedure whereby two independent Qualified Appraisers, one appointed by
the lessor and one by the lessee, shall agree upon the value, period, amount or
determination then the subject of an appraisal, as follows:  If either the
lessor or the lessee shall determine that a value, period or amount of
determination to be determined under such lease or any related document cannot
timely be established by agreement, such party shall appoint its Qualified
Appraiser and give
<PAGE>

                                                                               3

notice thereof to the other party, which shall appoint its Qualified Appraiser
within 10 days thereafter.  If such other party does not appoint its Qualified
Appraiser within such ten day period, the determination of the first Qualified
Appraiser made within 20 days thereafter shall be conclusive and binding on the
lessor and the lessee.  If within 20 days after appointment of the second of the
two Qualified Appraisers, such Qualified Appraisers are unable to agree upon the
value, period, amount or determination in question, they jointly shall appoint a
third Qualified Appraiser within 10 days thereafter, or, if they do not do so,
either the lessor or the lessee may request the American Arbitration Association
office in Houston, Texas (or if no such office exists at such time, the American
Arbitration Association office in New York, New York), or any organization
successor thereto, to appoint the third Qualified Appraiser from a panel of
arbitrators knowledgeable on the subject of refinery land and asset valuations
in the Texas Gulf Coast area.  The decision of the third Qualified Appraiser
shall be given within 20 days after his appointment.  If three Qualified
Appraisers shall be so appointed, the average of all three determinations shall
be conclusive and binding on the lessor and the lessee unless the determination
of one Qualified Appraiser is disparate from the middle determination by more
than twice the amount by which the third determination is disparate from the
middle determination, in which case the determination of the most disparate
Qualified Appraiser shall be excluded and the average of the remaining two
determinations shall be conclusive and binding on the lessor and the lessee.
The obligation to pay the fees and expenses of Qualified Appraisers incurred in
connection with any Appraisal Procedure shall be divided equally between the
lessor and the lessee.

     "Auxiliary Facilities" has the meaning given such term in Article VI of the
      --------------------
Coker Complex Ground Lease.

     "Auxiliary Rights" has the meaning given such term in Article VI of the
      ----------------
Coker Complex Ground Lease.

     "Available Coker Company Maya" means, for any day, the sum of (a) the
      ----------------------------
Contract Quantity for such day, plus (b) the extent, if any, that the Available
                                ----
Coker Company Maya for the preceding day exceeds the Actual Crude Capacity for
such preceding day.

     "Available Coker Company VTBs" means, for any day, the sum of (a) the Coker
      ----------------------------
Company VTBs produced by the Crude Unit on such day, plus  (b) the extent, if
                                                     ----
any that Available Coker Company VTBs for the preceding day exceeds Actual Coker
Capacity for such preceding day.

     "Base Case Financial Model" shall mean the financial model described on
      -------------------------
Exhibit A to the Services and Supply Agreement.

     "BPD" has the meaning given such term in the Long-Term Oil Supply
      ---
Agreement.

     "Business Day" means any day other than Saturday, Sunday or a legal holiday
      ------------
in the United States of America.
<PAGE>

                                                                               4

     "Clark Equipment" means all Clark Refinery Property other than the
      ---------------
Ancillary Equipment.

     "Clark Hydrogen Supply Contract" means the Product Supply Agreement, dated
      ------------------------------
as of August 1, 1999, between Clark R&M and Air Products, Inc.

     "Clark Maya" means Maya Crude Oil purchased by Clark R&M.
      ----------

     "Clark Processing Fee" means, for any monthly period, the total fees due
      --------------------
the Coker Company from Clark R&M for processing services provided pursuant to
Sections 3.5, 4.2 and 4.3.

     "Clark R&M" means Clark Refining & Marketing, Inc., a Delaware corporation.
      ---------

     "Clark R&M Agreements" means, collectively, (i) the Services and Supply
      --------------------
Agreement, (ii) the Product Purchase Agreement, (ii) the Coker Complex Ground
Lease and (iv) the Ancillary Equipment Site Lease.

     "Clark Refinery Property" means all real and personal property owned by
      -----------------------
Clark R&M and located at the Refinery.

     "Coker" means the delayed coker to be constructed at the Refinery and
      -----
designated DCU 843.

     "Coker Company" means Port Arthur Coker Company L.P., a Delaware limited
      -------------
partnership.

     "Coker Company Crude Oil Volume" means, on any day, the volume, stated in
      ------------------------------
BPD, of Coker Company-owned crude oil processed through the Crude Unit.

     "Coker Company Maya" means Maya Crude Oil purchased by the Coker Company.
      ------------------

     "Coker Complex" means, collectively, the Coker, the Hydrocracker, the
      -------------
Sulfur Plant, the Sour Water Stripper, the Amine Treating Unit and the Coker
Complex Offsites.

     "Coker Complex Design Capacity" means with respect to the Coker Complex,
      -----------------------------
its nameplate capacity, stated in BPD, to process feedstocks.

     "Coker Complex Ground Lease" means the Coker Complex Ground Lease and
      --------------------------
Blanket Easement Agreement, dated as of August 19, 1999, between Clark R&M and
the Coker Company.

     "Coker Complex Ground Lease Term" has the meaning given such term in
      -------------------------------
Article XX of the Coker Complex Ground Lease.
<PAGE>

                                                                               5

     "Coker Complex Initial Term" means the period commencing on August 19, 1999
      --------------------------
and ending on August 19, 2029.

     "Coker Complex Leasehold" has the meaning given such term in Section 2.1 of
      -----------------------
the Coker Complex Ground Lease.

     "Coker Complex Offsites" means, collectively, (a) the control room, flare,
      ----------------------
cooling tower, sulfur loading facilities and power station no. 6 that are being
constructed pursuant to the EPC Contract and (b) the coker feed tank nos. 108
and 109 that are being modified pursuant to the EPC Contract.

     "Coker Complex Renewal Term" means each period following the end of the
      --------------------------
Initial Term with respect to which Lessee has the option to renew the Coker
Complex Ground Lease pursuant to Article XX of the Coker Complex Ground Lease.

     "Coker Complex Site" has the meaning give such term in Section 2.1(a) of
      ------------------
the Coker Complex Ground Lease.

     "Coker Design Capacity" means with respect to the Coker, its nameplate
      ---------------------
capacity, stated in BPD, to process feedstocks.

     "Collateral Trustee" means the collateral trustee granted a security
      ------------------
interest, on behalf of the Financing Parties, in the Senior Debt pursuant to the
Financing Documents and any successor collateral trustee thereunder.

     "Common Security Agreement" means the Common Security Agreement, dated as
      -------------------------
of August 19, 1999, among the Coker Company, the Funding Company, Sabine,
Neches, Bankers Trust Company, as Collateral Trustee and Depositary Bank,
Deutsche Bank AG, New York Branch, as Administrative Agent, Winterthur
International Insurance Company Limited, as Oil Payment Insurers Administrative
Agent and HSBC Bank USA, as Capital Markets Trustee,

     "Contract Quantity" means (a) for any day when the Long-Term Oil Supply
      -----------------
Agreement is in effect and PMI has not reduced the volume of Maya available to
the Coker Company pursuant thereto, the "Contract Quantity" in effect on such
day pursuant to the Long-Term Oil Supply Agreement or such lesser amount of Maya
Crude Oil as may be purchased thereunder pursuant to Section 8.2 of the Long-
Term Oil Supply Agreement, and (b) for any other day, the amount of Maya Crude
Oil sufficient to operate the Coker at eighty percent of Actual Coker Capacity.

     "Contractor" means Foster Wheeler USA Corporation, a Delaware corporation.
      ----------

     "Crude Design Capacity" means with respect to the Ancillary Equipment, its
      ---------------------
nameplate capacity, stated in BPD, to process heavy crude oil.

<PAGE>

                                                                               6

     "Crude Unit" means the crude unit and vacuum tower located at the Refinery
      ----------
and collectively designated AVU-146.

     "CRU 1344 Hydrotreater" means the naphtha hydrotreater located at the
      ---------------------
Refinery and designated CRU 1344.

     "Easements" has the meaning given such term in Section 2.2 of the Coker
      ---------
Complex Ground Lease.

     "EPC Contract" means the Contract for Engineering, Procurement and
      ------------
Construction Services, dated as of July 12, 1999, between the Coker Company and
the Contractor, as amended, supplemented or otherwise modified from time to
time.

     "Event of Force Majeure" means any event or circumstance if (i) such event
      ----------------------
or circumstance is beyond the reasonable control of the affected party and (ii)
such event or circumstance is not the direct or indirect result of a party's
negligence or the failure of such party to perform any of its obligations under
the applicable Clark R&M Agreement, including, without limitation:

     1. any interruption or cessation in delivery of Coker Company Maya to the
        Refinery, whether or not due to an event of force majeure under the
        Long-Term Oil Supply Agreement;

     2. acts of God, epidemic, earthquake, landslide, lightning, fire,
        explosion, accident, tornado, drought, blight, famine, flood, hurricane,
        or other extraordinary weather conditions more severe than those
        experienced at any time in the last thirty (30) years for the geographic
        area of the Refinery;

     3. acts of a public enemy, war (declared or undeclared), blockade,
        insurrection, riot or civil disturbance, sabotage, quarantine, or any
        exercise of the power of eminent domain, police power, condemnation or
        other taking by or on behalf of any public, quasi-public or private
        entity;

     4. laws, rules, regulations, orders, judgments or other acts of any
        foreign, federal, state or local court, administrative agency,
        governmental body or authority;

     5. strikes, boycotts or lockouts, except any such strike, boycott or
        lockout that is not national or industry-wide that involves the
        employees of Clark R&M; and

     6. a partial or entire interruption or other failure of (a) the supply of
        electricity, water, wastewater treatment, steam, hydrogen or other
        utilities
<PAGE>

                                                                               7

        to the Refinery or any part thereof, or (b) pipeline service, ship or
        barge service, dock access or usage or other transportation facilities.

     "Excess Coker Capacity" means, for any day, the extent that Actual Coker
      ---------------------
Capacity for such day exceeds the capacity necessary for the Coker to process
the Available Coker Company VTBs for such day.

     "Excess Coker Capacity Option" has the meaning given such term in Section
      ----------------------------
4.2(a) of the Services and Supply Agreement.

     "Excess Crude Capacity" means, for any day, the extent that Actual Crude
      ---------------------
Capacity for such day exceeds the capacity necessary for the Ancillary Equipment
to process the Available Coker Company Maya for such day and the light crude oil
necessary to process such Available Coker Company Maya.

     "Excess Crude Capacity Option" has the meaning given such term in Section
      ----------------------------
3.5(b) of the Services and Supply Agreement.

     "Excess Hydrocracker Capacity" means, for any day, the extent that Actual
      ----------------------------
Hydrocracker Capacity for such day exceeds the capacity necessary for the
Hydrocracker to process Coker Company VGO produced by the Coker on such day.

     "Excess Hydrocracker Capacity Option" has the meaning given such term in
      -----------------------------------
Section 4.3(a) of the Services and Supply Agreement.

     "Fair Market Rental Value" shall mean, with respect to any land and/or
      ------------------------
equipment to be leased pursuant to a lease, the value, which shall not in any
event be less than zero, that would be obtained in an arm's length transaction
for cash between an informed and willing lessee and an informed and willing
lessor, neither of whom is under any compulsion to lease, for the use of such
land and/or equipment for a given period, without regard, in the case of land,
(i) to the value of any equipment or improvements that are not included in such
lease but which are located on such land, (ii) to the value of any reversionary
interest of the lessor in any equipment or improvements located on such land,
whether or not included in such lease, or (iii) to the highest and best use of
such land.

     "Final Completion" has the meaning given such term in the EPC Contract.
      ----------------

     "Financial Close" means the date when the initial funding of the Senior
      ---------------
Debt has occurred.

     "Financing Documents" has the meaning given such term in the Common
      -------------------
Security Agreement.

     "Financing Parties" means any lender or note purchaser that may at any time
      -----------------
be party to the Financing Documents and any trustee or agent acting on their
behalf.
<PAGE>

                                                                               8

     "Funding Company" means Port Arthur Finance Corp., a Delaware corporation.
      ---------------

     "GFU 241" means the distillate hydrotreater located at the Refinery and
      -------
designated GFU 241.

     "GFU 242" means the distillate hydrotreater located at the Refinery and
      -------
designated GFU 242.

     "GFU 243" means the distillate hydrotreater located at the Refinery and
      -------
designated GFU 243.

     "Guaranteed Values" has the meaning given such term in the EPC Contract.
      -----------------

     "Heavy Oil Processing Facility" means, collectively, the Coker Complex and
      -----------------------------
the Ancillary Equipment.

     "Hydrocracker" or "HCU 942" means the hydrocracker to be constructed at the
      ------------      -------
Refinery and designated HCU 942.

     "Hydrogen" means hydrogen purchased by the Coker Company pursuant to the
      --------
Hydrogen Supply Agreement.

     "Hydrogen Supply Agreement" means the Supply Agreement, dated as of
      -------------------------
August 1, 1999, between the Coker Company and Air Products, Inc.

     "Independent Engineer" means Purvin & Gertz, Inc., or successor thereto
      --------------------
appointed pursuant to the Financing Documents.

     "Inflation Factor" shall mean, for any month, (a) the most current Producer
      ----------------
Price Index published by the U.S. Department of Labor, Bureau of Statistics,

divided by, (b) the Producer Price Index on August 19, 1999.
----------

     "Labor Costs" shall mean, with respect to any service provided by Clark
      -----------
R&M, all reasonable direct labor costs of Clark R&M in performing such service
including wages, salaries, overtime charges, reasonable and customary bonuses,
payroll insurance and taxes and holidays, vacations, group medical, dental and
life insurance and other employee benefits.

     "LCO" means light cycle oil.
      ---

     "Lessor Ancillary Equipment Upgrade" shall have the meaning given such term
      ----------------------------------
in Section 6.1 of the Ancillary Equipment Site Lease.

     "Lien" any mortgage, security interest, pledge, hypothecation, encumbrance
      ----
or lien (statutory or other) of any kind or nature whatsoever.
<PAGE>

                                                                               9

     "Long-Term Oil Supply Agreement" means the Maya Crude Oil Sale Agreement,
      ------------------------------
dated as of March 10, 1998, between PMI and Clark R&M, as amended by the First
Amendment and Supplement to the Maya Crude Oil Sales Agreement, dated as of
August 19, 1999, and as assigned by Clark R&M to the Coker Company pursuant to
the Long-Term Oil Supply Agreement Assignment.

     "Long-Term Oil Supply Agreement Assignment" means the Assignment of the
      -----------------------------------------
Long-Term Oil Supply Agreement, dated as of August 19, 1999, by Clark R&M to the
Coker Company.

     "Maya Crude Oil" means Mexican crude oil of the "Maya" type, as more
      --------------
particularly described in the Long-Term Oil Supply Agreement and, to the extent
necessary, such alternative crude oil(s) and/or other feedstock(s) that may be
used to produce the Required Product Mix.

     "Neches" mean Neches River Holding Corp., a Delaware corporation.
      ------

     "Operating Year" means (i) the period beginning on the Start-up Date and
      --------------
ending on the last day of the calendar year in which the Start-up Date occurs
and (ii) each calendar year thereafter.  All annual amounts set forth in the
Clark R&M Agreements shall be adjusted pro rata for the first Operating Year.

     "Performance Test Standards" has the meaning given such term in the EPC
      --------------------------
Contract.

     "Permit" means any valid waiver, exemption, variance, franchise, permit,
      ------
authorization, license or similar order of or from any federal, state, county,
municipal, regional, environmental or other governmental body, instrumentality,
agency, authority, court or other body having jurisdiction over the Refinery,
the Coker Complex or the Ancillary Equipment or the performance of any
obligation under any Clark R&M Agreement, any Project Document or any other
agreement in connection therewith.

     "Permitted Liens" means (i) the respective rights and interests created by
      ---------------
or under the Financing Documents and the Project Documents, (ii) Liens for Taxes
that either are not delinquent or are being contested in good faith and by
appropriate proceedings diligently conducted, so long as such proceedings do not
(a) involve a substantial risk of foreclosure, forfeiture, loss or sale of any
portion of the Clark Refinery Property subject to the Ancillary Equipment Site
Lease or the Coker Complex Ground Lease or interest therein, (b) interfere with
the use, possession or disposition of any Clark Refinery Property subject to the
Ancillary Equipment Site Lease or the Coker Complex Ground Lease or interest
therein or (c) interfere with the payment of rent under the Ancillary Equipment
Site Lease or the Coker Complex Ground Lease; (iii) materialmen's, mechanics',
workmen's, repairmen's, employees', carriers', warehousemen's and other like
Liens arising in the ordinary course of business for amounts that either are not
more than 30 days past due or are being contested in good faith by appropriate
proceedings, so long as such proceedings satisfy the conditions for the
continuation of
<PAGE>

                                                                              10

proceedings to contest Taxes set forth in clause (ii) above; (iv) Liens of any
of the types referred to in clauses (ii) and (iii) above that have been bonded
for the full amount in dispute (or as to which other security arrangements
reasonably satisfactory to the Collateral Trustee have been made); (v) Liens
securing judgments, decrees or orders of any court (i) that are not currently
dischargeable or (ii) that have been discharged or stayed or appealed within
thirty (30) days after the date of such judgment, decree or order (in the case
of a stay or appeal, during the period of such stay or appeal); (vi) other Liens
that would not impair (x) the ability of the Coker Company or its successors,
assigns or subtenants to operate the Coker Complex in accordance with the Base
Case Financial Model or (y) any of the security interests granted, or to be
granted, by the Coker Company to the Financing Parties pursuant to the Financing
Documents, (vii) with respect to the Ancillary Equipment Site Lease, the Liens
listed on Schedule I thereto; and (viii) with respect  to the Coker Complex
Ground Lease, the Liens listed on Schedule I thereto.

     "Permitted Reimbursable Expenses" shall mean, with respect to any service
      -------------------------------
provided by Clark R&M, any reasonable expense or expenditure incurred in
performance of such service including, without limitation, (i) Labor Costs, (ii)
purchases of spare parts, tools, equipment, consumables, materials and other
supplies necessary for performance of such service and (iii) direct cost of
subcontract labor or services needed to perform such service.

     "Person" an individual, partnership, corporation, business trust, joint
      ------
stock company, trust, unincorporated association, joint venture, governmental
authority or other entity of whatever nature.

     "PMI" means P.M.I. Comercio Internacional, S.A. de C.V., a corporation
      ---
organized under the laws of Mexico.

     "Product Purchase Agreement" means the Product Purchase Agreement, dated as
      --------------------------
of August 19, 1999, between Clark R&M and the Coker Company, as amended,
supplemented or otherwise modified from time to time.

     "Products" means each product described under the heading "Product" on
      --------
Exhibits A-1 through A-42 to the Product Purchase Agreement.

     "Project Documents" means, collectively, the Services and Supply Agreement,
      -----------------
the Product Purchase Agreement, the Long-Term Oil Supply Agreement, the EPC
Contract, the Coker Complex Ground Lease, the Ancillary Equipment Site Lease and
the Hydrogen Supply Agreement.

     "Prudent Industry Practice" means those practices, methods, equipment,
      -------------------------
specifications and standards of safety and performance, as the same may change
from time to time, as are commonly used in refinery facilities in the United
States of a type and size similar to the Refinery.

     "Qualified Appraiser" means an appraisal firm with a national reputation
      -------------------
and experience in appraising facilities of a nature and type similar to the
Refinery.
<PAGE>

                                                                              11

     "Reconciliation Statement" has the meaning given such term in Section
      ------------------------
7.2(a) of the Services and Supply Agreement.

     "Refinery" means, collectively, the existing oil refinery owned by Clark
      --------
R&M located in Port Arthur, Texas, the Ancillary Equipment and the Coker
Complex.

     "Regulated Utilities" has the meaning given such term in Section 5.5(f) of
      -------------------
the Services and Supply Agreement.

     "Required Product Mix" means, from time to time, the quantity and quality
      --------------------
specifications of products to be produced by the Heavy Oil Processing Facility
pursuant to Section 2.2 of the Product Purchase Agreement.

     "Sabine" means Sabine River Holding Corp., a Delaware corporation.
      ------

     "Senior Debt" has the meaning given such term in the Common Security
      -----------
Agreement.

     "Senior Debt Obligations" means the obligations to pay principal and
      -----------------------
interest on the disbursed Senior Debt, and all commissions, fees, indemnitees,
prepayment premiums and other amounts payable to the senior lenders under the
Financing Documents.

     "Services" has the meaning set forth in Section 2.1  of  the Services and
      --------
Supply Agreement.

     "Services and Supply Agreement" means the Services and Supply Agreement,
      -----------------------------
dated as of August 19, 1999, between Clark R&M and the Coker Company, as
amended, supplemented or otherwise modified from time to time.

     "Sour Water Stripper" means the sour water stripper to be constructed at
      -------------------
the Refinery and designated SWS-8747.

     "Standards" means, in addition to any other standards set forth in the EPC
      ---------
Contract, the technical requirements of the Project Documents, generally
accepted standards of professional care, skill, diligence and competence
applicable to engineering and construction and project management practices,
good refinery and petrochemical industry practices for oil refineries of similar
size, type and design to the Refinery, manufacturer's specifications and
warranty requirements and all Applicable Laws.

     "Start-up Date" means the date on which hydrocarbons are first introduced
      -------------
into the Coker Complex for the processing of test runs under the EPC Contract.

     "Start-up Period" means the period from the Start-up Date until Final
      ---------------
Completion.
<PAGE>

                                                                              12

     "Sulfur Plant" means the sulfur plant to be constructed at the Refinery and
      ------------
designated SRU 545.

     "Supplies" has the meaning set forth in Section 2.1 of the Services and
      --------
Supply Agreement.

     "Tax" means, with respect to any site or parcel of land and the
      ---
improvements thereon, all real estate taxes and assessments, including
substitutes therefor or supplements thereto, assessed upon, levied against or
imposed on such land and improvements located thereon which accrue and are due
and payable during the term of the Coker Complex Ground Lease.  Notwithstanding
anything to the contrary contained herein, the term "Taxes" shall not include
any franchise, income, corporation, inheritance, succession, gift, estate,
realty transfer, capital or other tax which may be charged or assessed against
Lessor or any income, excess profit or revenue tax or any other tax which may be
assessed against or become a lien upon the Coker Complex Site or the rent
accruing therefrom.

     "Total Crude Oil Volume" means, for any day, the total daily volume, stated
      ----------------------
in BPD, of crude oil processed by the Crude Unit.

     "Transfer and Assignment Agreement" means the Transfer and Assignment
      ---------------------------------
Agreement, dated as of August 19, 1999, between Clark R&M and the Coker Company,
as amended, supplemented or otherwise modified from time to time.

     "VGO" means vacuum gas oil.
      ---

     "VTBs" means vacuum tower bottoms.
      ----

     "Warranties" means the requirements of all warranties and guarantees
      ----------
applicable to equipment and structures constituting the Coker Complex or
the Ancillary Equipment provided by the Contractor, subcontractors,
vendors,suppliers or others.

<PAGE>

                                                                    Schedule 3.1
                                                   Services and Supply Agreement

                      CRUDE SUPPLY MANAGEMENT SERVICES

7.   Scope.
     -----

     1.1.  Long-Term Oil Supply Agreement

           Clark R&M shall administer the Long-Term Oil Supply Agreement on
           behalf of the Coker Company and perform all the Coker Company's
           obligations (other than payment obligations) and exercise its rights
           thereunder including, without limitation, the following:

           a.    providing quarterly progress reports to PMI with respect to (i)
                 construction under the EPC Contract and (ii) the Ancillary
                 Equipment Upgrade

           b.    providing PMI timely notice of the occurrence of events of
                 force majeure or other occurrences that may affect the Coker
                 Company's ability to perform its material obligations under the
                 Long-Term Oil Supply Agreement

           c.    furnishing monthly lifting programs to PMI (including, without
                 limitation, the quantity of Maya to be delivered each month and
                 the tankers that are to deliver such Maya) and cooperating with
                 PMI to agree on actual monthly lifting programs for deliveries
                 of Maya to the Refinery, all in accordance with Section 21.1 of
                 the Long-Term Oil Supply Agreement

           d.    engagement of tankers on behalf of the Coker Company for
                 delivery of Maya

           e.    cooperate with PMI (i) to determine if an alternative pricing
                 mechanism is required if so notified by PMI pursuant to Section
                 10.2 of the Long-Term Oil Supply Agreement and (ii) if so, to
                 determine the parameters of such mechanism

           f.    monitor and keep records of on-going calculations of the
                 Differential Guarantee, Quarterly Shortfalls and Quarterly
                 Surpluses (each as defined in the Long-Term Oil Supply
                 Agreement)

     1.2   Other Crude Oil Contracts

           a.    Clark R&M shall administer and perform all the Coker Company's
                 obligations (other than payment obligations) and exercise its
                 rights under all other crude oil contracts procured on behalf
                 of the Coker Company pursuant to Section 3.1 of the Services
                 and Supply Agreement.

                                     -13-
<PAGE>

                                                                    Schedule 3.1
                                                   Services and Supply Agreement

          b.   Clark R&M shall procure, negotiate and administer such contracts
               in a manner that ensures the timely delivery to the Refinery of
               the volumes and types of crude oil necessary for the on-going
               production of the Required Product Mix.

8.   Applicable Price.
     ----------------

     2.1  The Coker Company shall reimburse Clark R&M for all Permitted
          Reimbursable Expenses (other than Labor Costs) incurred by Clark R&M
          in connection with providing crude supply management services to the
          Coker Company, including, without limitation, those expenses described
          in 3.1 below. The allocation of Labor Costs incurred by Clark R&M in
          providing crude supply management services to the Coker Company shall
          be included in the charges to the Coker Company under Section 5.8 of
          the Services and Supply Agreement.

     2.2  In addition, the Coker Company shall pay Clark R&M a handling fee of
          $0.03 for each barrel of Coker Company-owned crude oil delivered to
          the Refinery.

9.   Additional Terms.
     ----------------

     3.1  Clark R&M shall pass through charges to the Coker Company for the
          following Permitted Reimbursable Expenses associated with the
          transportation of crude, including without limitation, the following
          fees:

            Customs Fees
            MPA Fees
            Harbor Maintenance
            Merchandising Processing Fee

     3.2  The Coker Company is expected to be billed directly (as part of
          invoice for payment for crude oil purchases) by the applicable third
          party for certain expenses associated with the transportation of
          crude, including, without limitation, charges related to the
          following:

            Marine Freight
            Freight
            OPA
            Lightering
            Marine Losses
            Insurance
            Inspection
            Pipeline Tariffs (excluding CPAP)
            Pipeline Losses
            Pour Depressant

                                     -14-
<PAGE>

                                                                    Schedule 3.1
                                                   Services and Supply Agreement

            Viscosity Surcharge
            Superfund Tax
            State Tax
            Oil Spill Fees

                                     -15-
<PAGE>

                                                                    Schedule 3.2
                                                   Services and Supply Agreement

                      DOCK, PIPELINE AND STORAGE SERVICES

1.   Scope.
     -----

     1.1.  Clark R&M shall provide and coordinate all dock, pipeline and spot
           storage services needed to bring Maya and other Coker Company crude
           oil to the Heavy Oil Processing Facility. As of the date hereof,
           Clark R&M intends to provide such services by means of the following:

             a.  the Clark R&M-owned docks (the "Clark Docks") and tank farms;

             b.  the dock owned by Sunoco, Inc. located in Nederland, Texas
                 (the "Sun Dock") and the related storage facilities ("Sun
                 Storage");

             c.  the Refinery pipeline system (the "Refinery Pipeline);

             d.  the pipeline system located at 9405 West Port Arthur Road,
                 Beaumont, Texas and commonly know as the Lucas Station and the
                 related storage facilities (the "Lucas Station"); and

             e.  other third party pipeline and terminal services.

     1.2   Clark R&M shall manage and coordinate vessel activities at the Clark
           Docks and the Sun Dock as necessary for the delivery of Maya and
           other Coker Company crude oil, including, without limitation,
           scheduling vessels, arranging berthing, vessel tie-up and release,
           connecting loading and unloading systems, furnishing standby and
           safety operators, taking product samples, operating the spill
           prevention system, preparing bills of lading and other required
           documentation and hiring tankermen and independent inspectors.

     1.3   Clark R&M shall manage and coordinate all other vessel and pipeline
           activities necessary for the delivery of Coker Company crude oil to
           the Heavy Oil Processing Facility, including, without limitation,
           scheduling vessels, pipelines, arranging berthing, vessel tie-up and
           release, connecting loading/unloading systems, furnishing
           standby/safety operators, taking product samples, operating spill
           prevention system and preparing bills of lading and other required
           documentation including the hiring of tankermen and independent
           inspectors.

     1.4   Clark R&M shall maintain the Clark Dock facilities in a condition
           suitable to meet the shipping requirements of the Coker Company and
           manage priority of Clark Dock usage in a manner consistent therewith.
<PAGE>

                                                                    Schedule 3.2
                                                   Services and Supply Agreement

2.   Applicable Price.
     ----------------

     2.1   Sun Dock to Refinery

           For each barrel of Coker Company crude oil delivered to the Refinery
           through the Sun Dock each month, the Coker Company shall pay Clark
           R&M the Sun Dock Fee plus the CPAP Tariff I during such month.
                                ----

           Where:

                  "Sun Dock Fee" means, for any month, the price per barrel
                  charged Clark R&M for use of the Sun Dock by Sunoco Oil, Inc.

                  "CPAP Tariff I" means, for any month, the per barrel tariff
                  charged Clark R&M by CPAP for crude oil delivered from the Sun
                  Dock known as the "Lucas Crude Petroleum Tariff"(origin
                  Nederland).

     2.2   Sun Storage

           For each barrel of Coker Company crude oil stored at Sun Storage each
           month, the Coker Company shall pay Clark R&M the Sun Spot Fee for
           each fifteen day period that such crude oil is stored at Sun Storage.

           Where:

                  "Sun Spot Fee" means, for any month, the price per barrel
                  charged by Sunoco, Inc. for each fifteen day period that crude
                  oil is stored at the Sun Storage.

     2.3   Clark Docks to Refinery (including interim storage, if necessary)

           For each barrel of Coker Company crude oil delivered to the Refinery
           through the Clark Docks each month, the Coker Company shall pay Clark
           R&M the Sun Dock Fee plus the CPAP Tariff I.
                                ----

     2.4   Third Party Pipelines to Refinery (including interim storage, if
           necessary)

           For each barrel of Coker Company crude oil delivered to the Refinery
           through Lucas Station from sources other than the Clark Docks or the
           Sun Dock each month, the Coker Company shall pay Clark R&M the CPAP
           Tariff II.

           Where:

                  "CPAP Tariff II" means, for any month, the price per barrel
                  charged Clark R&M by CPAP during such month for crude oil
                  delivered from Lucas

                                      -2-
<PAGE>

                                                                    Schedule 3.2
                                                   Services and Supply Agreement

                  Station to the Refinery from sources other than the Clark
                  Docks or the Sun Dock and known as the "Lucas Crude Petroleum
                  Tariff" (origin Lucas Station).

3.   Additional Terms.
     ----------------

     The following are the applicable rates, as of the date hereof, for the
     various fees to be charged the Coker Company by Clark R&M hereunder.

     3.1       Sun Dock Fee:       7 cents/bbl for the first 70,000 BPD then 6
                                   cents/bbl for each barrel over 70,000 BPD.

     3.2       Sun Spot Fee        9.5 cents/bbl (for fifteen days)

     3.3       CPAP Tariff I       23 cents/bbl.

     3.4       CPAP Tariff II      11 cents/bbl.

                                      -3-
<PAGE>

                                                                    Schedule 3.3
                                                   Services and Supply Agreement

                          CRUDE UNIT FEEDSTOCK SUPPLY

1.   Scope.
     -----

     1.1.   Clark R&M shall supply the Coker Company's requirements of overhead
            liquid from GFU 244 to AVU 146 ("Overhead Liquid") which is expected
            to have the following specifications:

            Property        Typical              Test Method
            --------        -------              -----------

            API Gravity     41.1 Typical         ASTM D-1298

     1.2    Clark R&M shall supply the Coker Company's requirement of refinery
            slop oil to AVU 146 ("Slop Oil").

2.   Measurement
     -----------

     2.1    Overhead Liquid

            Clark R&M shall sell and Coker Company shall purchase the "Coker
            Company Share" of the total input of this Overhead Liquid to AVU
            146. The Coker Company Share is defined as the total input of this
            Overhead Liquid multiplied by the Coker Company Crude Oil Volume
            divided by the Total Crude Oil Volume.

     2.2    Slop Oil

            Clark R&M shall sell and Coker Company shall purchase the "Coker
            Company Share" of the total input of this Feedstock to AVU 146. The
            Coker Company Share is defined as the total input of this Feedstock
            multiplied by the Coker Company Crude Oil Volume divided by the
            Total Crude Oil Volume.

3.   Applicable Price
     ----------------

     3.1    Overhead Liquid

            The arithmetic average of the high/low Platt's Oilgram Price Report
            U. S. Gulf Coast Waterborne posting for spot purchases of No. 2 (0.2
            wt% S diesel) for each publication day less 3.0 cents/gallon
            multiplied by the quantity of the Overhead Liquid delivered on that
            day.The price for non-publication day deliveries shall be the
            arithmetic average of the prices for the last proceeding publication
            day and the next following publication day.

     3.2    Slop Oil

            The volume weighted average price of crude oil charged to AVU 146
            for each day multiplied by the quantity of the Feedstock delivered
            on that day.
<PAGE>

                                                                    Schedule 3.3
                                                   Services and Supply Agreement

4.   Delivery Point/Risk of Loss:
     ---------------------------

     4.1   Overhead Liquid

           This Overhead Liquid shall be delivered by pipeline to the Coker
           Company and risk of loss shall pass at the battery limits of AVU 146.

     4.2   Slop Oil

           This Feedstock shall be delivered by pipeline to the Coker Company
           and risk of loss shall pass at the battery limits of AVU 146.

5.   Quantity Measurement:
     --------------------

     5.1   Overhead Liquid

           Quantity measurements shall be taken at the battery limits of AVU 146
           utilizing a meter to be designated upon completion of design
           engineering.

     5.2   Slop Oil

           Quantity measurements shall be calculated by changes in Refinery Slop
           inventory utilizing standard yield accounting methods.

6.   Quality Measurement
     -------------------

     6.1   Overhead Liquid

           Grab samples shall be taken as needed.

     6.2   Slop Oil

           None.

                                      -2-
<PAGE>

                                                                    Schedule 3.5
                                                   Services and Supply Agreement

                  CLARK PROCESSING FEE -- ANCILLARY EQUIPMENT

Clark R&M shall pay the Coker Company for the processing of Clark R&M-owned
crude oil each day according to the following formula:

          Crude Unit Fee + GFU 243 Fee + GFU 242 Fee + CRU 1344 Hydrotreater Fee

     Where:

     1.   Crude Unit Fee Definitions
          --------------------------

                    "Clark R&M Crude Fraction" means, for any day, (i) Excess
                     ------------------------
          Crude Capacity on such day, divided by (ii) Actual Crude Capacity on
                                      ----------
          such day.

                    "Crude Unit Fee" means, for any day, the sum of (i) Crude
                     --------------
          Unit Fixed, (ii) Crude Unit Non-Fuel Variable, (iii) Crude Unit Fuel
          Variable and (iv) Crude Unit Electricity Variable.

                    "Crude Unit Fixed" means, for any day, (i) 250,000
                     ----------------
          multiplied by (ii) Clark R&M Crude Fraction for such day, multiplied
          -------------                                             ----------
          by  (iii) $0.421, multiplied by (iv) the Inflation Factor for such
          --                -------------
          day.

                    "Crude Unit Non-Fuel Variable" means, for any day, (i)
                     ----------------------------
          Excess Crude Capacity for such day, multiplied by (ii) $0.005,
                                              -------------
          multiplied by (iv) the Inflation Factor for such day.
          -------------

                    "Crude Unit Fuel Variable" means, for any day, (i) Excess
                     ------------------------
          Crude Capacity for such day, multiplied by (ii) $0.239, multiplied
                                       -------------              ----------
          by (iii) (x) the Current Period Fuel Price, divided by (y) $2.24.
          --                                          ----------

                    "Crude Unit Electricity Variable" means, for any day, (i)
                     -------------------------------
          Excess Crude Capacity for such day, multiplied by (ii) $0.016,
                                              -------------
          multiplied by (iii) (x) the Current Period Electricity Price,
          -------------
          divided by (y) $0.029.
          ----------
<PAGE>

                                                                    Schedule 3.5
                                                   Services and Supply Agreement

     2.   GFU 243 Fee Definitions
          -----------------------

                    "Actual GFU 243 Capacity" means, for any day, the capacity,
                     -----------------------
          stated in BPD, of GFU 243 to process feedstreams.

                    "Clark R&M GFU 243 Capacity" means, for any day, (i) Actual
                     --------------------------
          GFU 243 Capacity, less, (ii) the capacity necessary for GFU 243 to
                            ----
          process Coker Company feedstreams from the Crude Unit on such day

                    "Clark R&M GFU 243 Fraction" means, for any day, (i) Clark
          R&M GFU 243 Capacity for such day, divided by (ii) Actual GFU 243
                                             ----------
          Capacity on such day.

                    "GFU 243 Fee" means, for any day, the sum of (i) GFU 243
                     ------- ---
          Fixed, (ii) GFU 243 Non-Fuel Variable, (iii) GFU 243 Fuel Variable
          and (iv) GFU 243 Electricity Variable.

                    "GFU 243 Fixed" means, for any day, (i) 43,000  multiplied
                     -------------                                  ----------
          by (ii) Clark R&M GFU 243 Fraction for such day, multiplied by
          --                                               -------------
          (iii) $0.380, multiplied by (iv) the Inflation Factor for such day.
                        -------------

                    "GFU 243 Non-Fuel Variable" means, for any day, (i) Clark
                     -------------------------
          R&M GFU 243 Capacity for such day, multiplied by (ii) $0.094,
                                             -------------
          multiplied by (iii) the Inflation Factor for such day.
          -------------

                    "GFU 243 Fuel Variable" means, for any day, (i) Clark R&M
                     ---------------------
          GFU 243 Capacity for such day, multiplied by (ii) $0.330, multiplied
                                         -------------              ----------
          by (iii) (x) the Current Period Fuel Price, divided by (y) $2.24.
          --                                          ----------

                    "GFU 243 Electricity Variable" means, for any day, (i) Clark
                     ----------------------------
          R&M GFU 243 Capacity for such day, multiplied by (ii) 0.042,
                                             -------------
          multiplied by (iii) (x) the Current Period Electricity Price,
          -------------
          divided by (y) $0.029.
          ----------

     6.   GFU 242 Fee Definitions
          -----------------------

                    "Actual GFU 242 Capacity" means, for any day, the capacity,
                     -----------------------
          stated in BPD, of GFU 242 to process feedstreams.

                    "Clark R&M GFU 242 Capacity" means, for any day, (i) Actual
                     --------------------------
          GFU 242 Capacity, less (ii) the capacity necessary for GFU 242 to
                            ----
          process Coker Company feedstreams from the Crude Unit on such day.

                    "Clark R&M GFU 242 Fraction" means, for any day, (i) Clark
                     --------------------------
          R&M GFU 242 Capacity for such day, divided by (ii) Actual GFU 242
                                             ----------
          Capacity on such day.

                                      -2-
<PAGE>

                                                                    Schedule 3.5
                                                   Services and Supply Agreement

                      "GFU 242 Fee"  means, for any day, the sum of (i) GFU 242
                       -----------
          Fixed, (ii) GFU 242 Non-Fuel Variable, (iii) GFU 242 Fuel Variable and
          (iv) GFU 242 Electricity Variable.

                    "GFU 242 Fixed" means, for any day, (i) 32,000  multiplied
                     -------------                                  ----------
          by (ii) Clark R&M GFU 242 Fraction for such day, multiplied by (iii)
          --                                               -------------
          $0.386, multiplied by (iv) the Inflation Factor for such day.
                  -------------

                    "GFU 242 Non-Fuel Variable" means, for any day, (i) Clark
                     -------------------------
          R&M GFU 242 Capacity for such day, multiplied by (ii) $0.017,
                                             -------------
          multiplied by (iii) the Inflation Factor for such day.
          -------------

                    "GFU 242 Fuel Variable" means, for any day, (i) Clark R&M
                     ---------------------
          GFU 242 Capacity for such day, multiplied by (ii) $ 0.342,
                                         -------------
          multiplied by (iii) (x) the Current Period Fuel Price, divided by
          -------------                                          ----------
          (y) $2.24.

                    "GFU 242 Electricity Variable" means, for any day, (i) Clark
                     ----------------------------
          R&M GFU 242 Capacity for such day, multiplied by (ii) $0.014,
                                             -------------
          multiplied by (iii) (x) the Current Period Electricity Price,
          -------------
          divided by (y) $0.029.
          ----------

     7.   CRU 1344 Hydrotreater Fee Definitions
          -------------------------------------

                    "Actual CRU 1344 Hydrotreater Capacity" means, for any day,
                     -------------------------------------
          the capacity, stated in BPD, of CRU 1344 Hydrotreater to process
          feedstreams.

                    "Clark R&M CRU 1344 Hydrotreater Capacity" means, for any
                     ----------------------------------------
          day, (i) Actual CRU 1344 Hydrotreater Capacity, less, (ii) the
                                                          ----
          capacity necessary for CRU 1344 Hydrotreater to process Coker
          Company feedstreams from the Crude Unit on such day

                    "Clark R&M CRU 1344 Hydrotreater Fraction" means, for any
                     ----------------------------------------
          day, (i) Clark R&M CRU 1344 Hydrotreater Capacity for such day,

          divided by (ii) Actual CRU 1344 Hydrotreater Capacity for such day.
          ----------

                    "CRU 1344 Hydrotreater Fee" means, for any day, the sum of
                     -------------------------
          (i) CRU 1344 Hydrotreater Fixed, (ii) CRU 1344 Hydrotreater Non-Fuel
          Variable, (iii) CRU 1344 Hydrotreater Fuel Variable and (iv) CRU 1344
          Hydrotreater Electricity Variable.

                    "CRU 1344 Hydrotreater Fixed" means, for any day, (i) 51,500
                     ---------------------------
          multiplied by (ii) Clark R&M CRU 1344 Hydrotreater Fraction for such
          -------------
          day, multiplied by (iii) $0.231, multiplied by (v) the Inflation
               -------------               -------------
          Factor for such day.

                                      -3-
<PAGE>

                                                                    Schedule 3.5
                                                   Services and Supply Agreement

                    "CRU 1344 Hydrotreater Non-Fuel Variable" means, for any
                     ---------------------------------------
          day, (i) Clark R&M CRU 1344 Hydrotreater Capacity, (ii) $0.020,

          multiplied by (iii) the Inflation Factor for such day.
          -------------

                    "CRU 1344 Hydrotreater Fuel Variable" means, for any day,
                     -----------------------------------
          (i) Clark R&M CRU 1344 Hydrotreater Capacity for such day,

          multiplied by (ii) $0.159, multiplied by (iii) (x) the Current
          -------------              -------------
          Period Fuel Price, divided by (y) $2.24.
                             ----------

                    "CRU 1344 Hydrotreater Electricity Variable" means, for any
                     ------------------------------------------
          day, (i) Clark R&M CRU 1344 Hydrotreater Capacity for such day,

          multiplied by (ii) $0.012, multiplied by (iii) (x) the Current
          -------------              -------------
          Period Electricity Price, divided by (y) $0.029.
                                    ----------

     8.   General Definitions
          -------------------

                    "Current Period Fuel Price" means, for any day, the MMBTU
                     -------------------------
          Price (as defined in Schedule 5.5.3) for the month in which such day
          occurs.

                    "Current Period Electricity Price" means, for any day, the
                     --------------------------------
          KWH Price (as defined in Schedule 5.5.1) for the month in which such
          day occurs.

                                      -4-
<PAGE>

                                                                    Schedule 4.1
                                                   Services and Supply Agreement

                            COKER COMPANY EMPLOYEES

1.   Nineteen (19) Coker - Front-End Operators

     Responsible for operating the charge/heater/fractionation/tank field
     sections of the Coker in a safe, environmentally sound, and efficient
     manner. This individual concentrates on the daily activities of operation.
     His/her input is required to resolve problems and optimize the facility
     along with the engineers and supervision of the facility. Daily duties
     include monitoring, documenting, and adjusting process variables to achieve
     the above. The functional operator assignments include Head Operators (4),
     Board Operators (4), Outside Operators (8) and Pool Operators (3).

2.   Eight (8) Coker - Coke Cutters

     Responsible for operating the coke cutting operations of the Coker in a
     safe, environmentally sound, and efficient manner. This individual
     concentrates on the daily activities of operation. His/her input is
     required to resolve problems and optimize the facility along with the
     engineers and supervision of the facility. Daily duties include drum
     opening/closing and coke cutting.

3.   Nineteen (19) Hydrocracker/Sulfur Plant Operators

     Responsible for operating the charge/heater/reactor/fractionation sections
     of the Hydrocracker and Sulfur Plant in a safe, environmentally sound, and
     efficient manner. This individual concentrates on the daily activities of
     operation. His/her input is required to resolve problems and optimize the
     facility along with the engineers and supervision of the facility. Daily
     duties include monitoring, documenting, and adjusting process variables to
     achieve the above. The functional operator assignments include Head
     Operators (4) Board Operators (4), Outside Operators (8) and Pool Operators
     (3).

4.   One (1) Accounting Manager

     Responsible for (i) for the accounting and administration of the
     intercompany agreements between Clark R&M and the Coker Company and all
     Financing Documents, (ii) reviewing and approving draft invoices and
     issuing final invoices to Clark R&M under the Services and Supply Agreement
     and the Product Purchase Agreement, (iii) making payments due to third
     parties under the Financing Documents and the Project Documents, (v)
     cooperating with any required third party audits, (vi) performing all Coker
     Company reporting and recordkeeping requirements under the Financing
     Documents, the Project Document and Applicable Law, (vii) administering
     Coker Company payroll, (viii) administering all other general accounting
     activities of the Coker Company including, without limitation, (a)
     maintaining general ledger balance sheet and expense accounts pertaining to
     the Heavy Oil Processing Facility, (b) processing and payment of invoices
<PAGE>

                                                                    Schedule 4.1
                                                   Services and Supply Agreement

     created by operation of the Heavy Oil Processing Facility and (c) ensuring
     that all Federal and State Tax guidelines are incorporated.

     Based on information to be provided to the Coker Company by Clark R&M, the
     accounting manager will also be responsible for the following:

          a.   Quantifying and documenting feedstocks to and Products from each
               Heavy Oil Processing Facility. Attaching value to each of these
               feedstocks and Products based on applicable fees in the Services
               and Supply Agreement and the Product Purchase Agreement.
               Monitoring all the laboratory data for such feedstocks and
               Products.

          b.   Monitoring and quantifying each Service provided to the Coker
               Company by Clark R&M.

          c.   Providing reconciliation analysis of the Coker Company's
               inventory, fixed assets and authorization for expenditures for
               capital or turnaround documentation.

          d.   Preparing and distributing monthly cost analysis

          e.   Providing planning and budgeting guidelines and participating in
               preparation of the Annual Budget and Operating Plan.

          f.   Coordinating the preparation and approval of unaudited quarterly
               and audited annual financial statements.

                                      -2-
<PAGE>

                                                                    Schedule 4.2
                                                   Services and Supply Agreement

                         CLARK PROCESSING FEE -- COKER

Clark R&M shall pay the Coker Company for the processing of Clark R&M-owned
feedstreams each day according to the following formula:

     Coker Fixed + Coker Non-Fuel Variable + Coker Fuel Variable + Coker
     Electricity Variable

          Where:

               "Clark R&M Coker Fraction" means, for any day, (i) (x) Actual
                ------------------------
          Coker Capacity on such day, less (y) Excess Coker Capacity on such
                                      ----
          day, divided by (ii) Actual Coker Capacity on such day.
               -------

               "Coker Fixed" means, for any day, (i) 80,000  multiplied by
                -----------                                  -------------
          (ii) Clark R&M Coker Fraction for such day, multiplied by  (iii)
                                                      -------------
          $4.114, multiplied by (iv) the Inflation Factor for such day.
                  -------------

               "Coker Non-Fuel Variable" means, for any day, (i) Excess Coker
                -----------------------
          Capacity for such day, multiplied by (ii) $0.045, multiplied by
                                 -------------              -------------
          (iii) the Inflation Factor for such day.

               "Coker Fuel Variable" means, for any day, (i) Excess Coker
                -------------------
          Capacity for such day, multiplied by (ii) $0.483, multiplied by
                                 -------------              -------------
          (iii) (x) the Current Period Fuel Price, divided by (y) $2.24.
                                                   ----------

               "Coker Electricity Variable" means, for any day, (i) Excess
                --------------------------
          Coker Capacity for such day, multiplied by (ii) $0.216, multiplied
                                       -------------              ----------
          by (iii) (x) the Current Period Electricity Price, divided by (y)
          --                                                 ----------
          $0.029.

               "Current Period Fuel Price" means, for any day, the MMBTU
                -------------------------
          Price (as defined in Schedule 5.5.3) for the month in which such day
          occurs.

               "Current Period Electricity Price" means, for any day, the KWH
                --------------------------------
          Price (as defined in Schedule 5.5.1) for the month in which such day
          occurs.
<PAGE>

                                                                    Schedule 4.3
                                                   Services and Supply Agreement

                     CLARK PROCESSING FEE -- HYDROCRACKER

Clark R&M shall pay the Coker Company for the processing of Clark R&M-owned
feedstreams each day according to the following formula:

     Hydrocracker Fixed + Hydrocracker Non-Fuel Variable + Hydrocracker Fuel
     Variable + Hydrocracker Electricity Variable

          Where:

               "Actual Hydrocracker Capacity" means, for any day, the
                ----------------------------
          capacity, stated in BPD, of the Hydrocracker to process feedstreams.

               "Clark R&M Hydrocracker Capacity" means, for any day, the
                -------------------------------
          volume of Clark R&M-owned feedstreams, stated in BPD, processed by the
          Hydrocracker on such day pursuant to Section 4.3 of the Services and
          Supply Agreement.

               "Clark R&M Hydrocracker Fraction" means, for any day, (i)
                -------------------------------
          Clark R&M Hydrocracker Capacity on such day, divided by (ii) Actual
                                                       -------
          Hydrocracker Capacity on such day.

               "Hydrocracker Fixed" means, for any day, (i) 35,000 multiplied
                ------------------                                 ----------
          by (ii) Clark R&M Hydrocracker Fraction for such day, multiplied by
          --                                                    -------------
          (iii) $4.888, multiplied by (iv) the Inflation Factor for such day.
                        -------------

               "Hydrocracker Non-Fuel Variable" means, for any day, (i) Clark
                ------------------------------
          R&M Hydrocracker Capacity for such day, multiplied by (ii) $0.221,
                                                  -------------
          multiplied by (iii) the Inflation Factor for such day.
          -------------

               "Hydrocracker Fuel Variable" means, for any day, (i) Clark R&M
                --------------------------
          Hydrocracker Capacity for such day, multiplied by (ii) $0.430,
                                              -------------
          multiplied by (iii) (x) the Current Period Fuel Price, divided by
          -------------                                          ----------
          (y) $2.24.

               "Hydrocracker Electricity Variable" means, for any day, (i)
                ---------------------------------
          Clark R&M Hydrocracker Capacity for such day, multiplied by (ii)
                                                        -------------
          $0.308, multiplied by (iii) (x) the Current Period Electricity
                  -------------
          Price, divided by (y) $0.029.
                 ----------

               "Current Period Fuel Price" means, for any day, the MMBTU
                -------------------------
          Price (as defined in Schedule 5.5.3) for the month in which such day
          occurs.

               "Current Period Electricity Price" means, for any day, the KWH
                --------------------------------
          Price (as defined in Schedule 5.5.1) for the month in which such day
          occurs.
<PAGE>

                                                                    Schedule 4.4
                                                   Services and Supply Agreement

                           HYDROGEN SUPPLY SERVICES

1.   Scope.
     -----

     1.1  Clark R&M shall administer the Hydrogen Supply Agreement on behalf of
          the Coker Company and otherwise perform the Coker Company's
          obligations (other than payment obligations) and exercise its rights
          thereunder including, without limitation, the following:

          1.   ordering the rate of flow and production of hydrogen needed by
               the Coker Company for operation of the Heavy Oil Processing
               Facility and, as necessary, requesting changes to such rates from
               time to time.

          2.   coordinating scheduled maintenance shutdowns and other
               maintenance activities at the Refinery and the Hydrogen Plant
               with Air Products, Inc.

          3.   monitoring compliance with required contract specifications for
               hydrogen delivered under the agreement including, without
               limitation, requesting additional analyses of batch samples and
               rejecting or waiving non-compliance with contract
               specifications.

          4.   monitoring the measurement and metering of hydrogen quantities
               delivered under the agreement including, without limitation,
               inspecting meters and other measurement equipment, witnessing
               recalibrations and challenging the accuracy of meters and other
               measurement equipment by requesting that the accuracy of such
               meters and other equipment be tested.

     1.2  Clark R&M shall supply the Coker Company's first requirements for
          hydrogen ("Clark High Pressure Hydrogen") for use at the Coker
          Complex. Clark High Pressure Hydrogen shall be delivered to the Coker
          Company for use in HCU 942 from the Spill Stream Hydrogen System
          owned and operated by Air Products for Clark R&M up to the maximum
          capacity of the Spill Stream Hydrogen System estimated to be 6.0
          MMSCF/D. Clark High Pressure Hydrogen shall meet the following
          specifications:

          Property           Specification            Test Method
          --------           -------------            -----------

          Hydrogen           99.9% Mole Minimum       UOP-539

     1.3  Clark R&M shall supply the Coker Company's additional requirements
          for hydrogen ("Clark Hydrocracker Purge Hydrogen") for use at the
          Coker Complex. Clark Hydrocracker Purge Hydrogen shall be delivered
          to the Coker Company for use in DCU 843 Naphtha Hydrotreater from the
          High Pressure Hydrogen Purge
<PAGE>

                                                                    Schedule 4.4
                                                   Services and Supply Agreement

          Gas from HCU 942. Clark Hydrocracker Purge Hydrogen shall meet the
          following specifications:

          Property               Specification            Test Method
          --------               -------------            -----------

          Hydrogen               80.0% Mole Minimum             UOP-539
          Higher                 500 BTU/SCF Typical            UOP-539
          Heating Value

     1.4  Clark R&M shall supply the Coker Company's requirements for hydrogen
          ("Clark Low Pressure Hydrogen") for use at the Ancillary Equipment and
          GFU 241. Clark Low Pressure Hydrogen shall be delivered to the
          Ancillary Equipment and GFU 241 from the Clark Hydrogen Gathering
          System. Clark Low Pressure Hydrogen shall meet the following
          specifications:

           Property           Specification            Test Method
           --------           -------------            -----------

          Hydrogen            70.0% Mole Minimum             UOP-539
          Higher              650 BTU/SCF Typical            UOP-539
          Heating Value

2.   Meters/Measurement.
     ------------------

     2.1  Clark High Pressure Hydrogen

          Clark High Pressure Hydrogen quantity measurements shall be taken at
          the Spill Stream Hydrogen System meter owned and operated by Air
          Products for Clark R&M.

     2.2  Clark Hydrocracker Purge Hydrogen

          Clark Hydrocracker Purge Hydrogen is calculated as a portion of the
          Total Hydrocracker Purge Hydrogen which quantity shall be measured at
          DCU 843 meter FE-3636. The Clark Hydrocracker Purge Hydrogen is
          calculated as follows:

          Clark Hydrocracker
          Purge Hydrogen =    Total Hydrocracker Purge Hydrogen * (Light Cycle
                              Oil to HCU 942 + Heavy Gas Oil from DCU 843 to HCU
                              942 * (1 - Coker Company Crude Oil Volume / Total
                              Crude Oil Volume) + Heavy Gas Oil from AVU 146 to
                              HCU 942 * (1 - Coker Company Crude Oil Volume /
                              Total Crude Oil Volume )) / (Light Cycle Oil to
                              HCU 942 + Heavy Gas Oil from DCU 843 to HCU 942 +
                              Heavy Gas Oil from AVU 146 to HCU 942)

                                      -2-
<PAGE>

                                                                    Schedule 4.4
                                                   Services and Supply Agreement

          Where:

          Light Cycle Oil to HCU 942, Heavy Gas Oil from DCU 843 to HCU 942,
          Heavy Gas Oil from AVU 146 to HCU 942, Coker Company Crude Oil Volume,
          and Total Crude Oil Volume are defined in Exhibit A-18 of the Product
          Purchase Agreement.

     2.3  Clark Low Pressure Hydrogen

          Clark R&M Low Pressure Hydrogen quantity measurements shall be
          calculated for the Ancillary Equipment and GFU 241 as follows:

          2.3.1   Coker Company GFU 241 Hydrogen

                  Coker Company GFU 241 Hydrogen is calculated as a portion of
                  the Total GFU 241 Make-up Hydrogen which quantity shall be
                  measured at GFU 241 meter FI-105M. The Coker Company GFU 241
                  Hydrogen is calculated as follows:

                  Coker Company GFU
                  241 Hydrogen =        Total GFU 241 Make-up Hydrogen * Coker
                                        Company Crude Oil Volume / Total Crude
                                        Oil Volume

                  Where:

                  Coker Company Crude Oil Volume and Total Crude Oil Volume are
                  defined in the Product Purchase Agreement.

          2.3.1   Coker Company GFU 242 Hydrogen

                  Coker Company GFU 242 Hydrogen is calculated as a portion of
                  the Total GFU 242 Make-up Hydrogen which quantity shall be
                  measured at GFU 242 meter FI-205M. The Coker Company GFU 242
                  Hydrogen is calculated as follows:

                  Coker Company GFU
                  242 Hydrogen =        Total GFU 242 Make-up Hydrogen * Total
                                        Feed to GFU 242 - Unfinished Jet from
                                        AVU 146 drawn from inventory * Coker
                                        Company Crude Oil Volume / Total Crude
                                        Oil Volume

                  Where:

                                      -3-
<PAGE>

                                                                    Schedule 4.4
                                                   Services and Supply Agreement

                  Total Feed to GFU 242, Unfinished Jet from AVU 146 drawn from
                  inventory, Coker Company Crude Oil Volume, and Total Crude Oil
                  Volume are defined in Exhibit A-33 of the Product Purchase
                  Agreement.

          2.3.3   Coker Company GFU 243 Hydrogen

                  Coker Company GFU 243 Hydrogen is calculated as a portion of
                  the Total GFU 243 Make-up Hydrogen which quantity shall be
                  measured at GFU 243 meter FIC-143. The Coker Company GFU 243
                  Hydrogen is calculated as follows:

                  Coker Company GFU

                  243 Hydrogen =        Total GFU 243 Make-up Hydrogen *
                                        ((Total Volume of Diesel from AVU 146 -
                                        Diesel Charge Volume to GFU 241 + Total
                                        Volume of Light Gas Oil from DCU 843 ) *
                                        Coker Company Crude Oil Volume / Total
                                        Crude Oil Volume - Coker Company Share
                                        of the Excessed Unfinished Diesel ) /
                                        Total Charge Volume to GFU 243

                  Where:

                  Total Feed to GFU 243, Total Volume of Diesel from AVU 146,
                  Diesel Charge Volume to GFU 241, Total Volume of Light Gas Oil
                  from DCU 843, Coker Company Share of the Excessed Unfinished
                  Diesel, Coker Company Crude Oil Volume, and Total Crude Oil
                  Volume are defined in Exhibit A-37 of the Product Purchase
                  Agreement.

          2.3.4   Coker Company 1344 Naphtha Hydrotreater Hydrogen

                  Coker Company 1344 Naphtha Hydrotreater Hydrogen is calculated
                  as a portion of the Total 1344 Naphtha Hydrotreater Make-up
                  Hydrogen which quantity shall be measured at 1344 Naphtha
                  Hydrotreater meter FR-857. The Coker Company 1344 Naphtha
                  Hydrotreater Hydrogen is calculated as follows:

                  Coker Company 1344
                  Naphtha
                  Hydrotreater
                  Hydrogen =       Total 1344 Naphtha Hydrotreater Make-up
                                   Hydrogen * (Coker Naphtha to Naphtha
                                   Hydrotreater 1344 + Total Unfinished
                                   Naphtha - Excessed Unfinished Naphtha) *
                                   Coker Company

                                      -4-
<PAGE>

                                                                    Schedule 4.4
                                                   Services and Supply Agreement

                                   Crude Oil Volume / Total Crude Oil Volume /
                                   (Total Naphtha Hydrotreater Feed )

                  Where:

                  Total Naphtha Hydrotreater Feed Coker Naphtha to Naphtha
                  Hydrotreater 1344, Total Unfinished Naphtha, Excessed
                  Unfinished Naphtha, Coker Company Crude Oil Volume, and Total
                  Crude Oil Volume are defined in Exhibit A-26 of the Product
                  Purchase Agreement.

     3.   Delivery Point/Risk of Loss.
          ----------------------------

          3.1  Clark High Pressure Hydrogen

               Clark High Pressure Hydrogen shall be delivered by pipeline and
               title to, and risk of loss for, such hydrogen shall pass to the
               Coker Company at the battery limit of Air Products Hydrogen
               Plant.

          3.2  Clark Hydrocracker Purge Hydrogen

               Clark Hydrocracker Purge Hydrogen shall be delivered by pipeline
               and title to, and risk of loss for, such hydrogen shall pass to
               the Coker Company at the battery limit of HCU 942.

          3.3  Clark Low Pressure Hydrogen

               Clark Low Pressure Hydrogen shall be delivered by pipeline and
               title to, and risk of loss for, such hydrogen shall pass to the
               Coker Company at the battery limit of each unit described in the
               Ancillary Equipment Lease and GFU 241.

     4.   Applicable Price.
          ----------------

          4.1  Hydrogen Supply Contract

               The Coker Company shall pay Clark R&M for all Permitted
               Reimbursable Expenses incurred by Clark R&M each month in
               administering the Hydrogen Supply Contract.

          4.2  Clark High Pressure Hydrogen

                                      -5-
<PAGE>

                                                                    Schedule 4.4
                                                   Services and Supply Agreement

               The Coker Company shall pay Clark R&M for Clark High Pressure
               Hydrogen supplied to the Coker Company each month the actual cost
               paid for hydrogen under contract with Air Products.

          4.3  Clark Hydrocracker Purge Hydrogen

               The Coker Company shall pay Clark R&M for contained hydrogen in
               the Clark Hydrocracker Purge Hydrogen supplied to the Ancillary
               Equipment and GFU 241 each month the actual cost paid for
               hydrogen under contract with Air Products. For the balance of the
               contents in the Clark Hydrocracker Purge Hydrogen, the Coker
               Company shall pay Clark R&M the weighted average delivered cost
               of natural gas purchased by Clark R&M in dollars per MMBTU.

          4.4  Clark Low Pressure Hydrogen

               The Coker Company shall pay Clark R&M for contained hydrogen in
               the Clark Low Pressure Hydrogen supplied to the Ancillary
               Equipment each month the actual cost paid for hydrogen under
               contract with Air Products. For the balance of the contents in
               the Clark Low Pressure Hydrogen, the Coker Company shall pay
               Clark R&M the weighted average delivered cost of natural gas
               purchased by Clark R&M in dollars per MMBTU.

          4.5  Power Charges and Credits.

               4.5.1     Power Charges

               The Coker Company shall pay Clark R&M for power consumed by Air
               Products' for the manufacture and delivery of High Pressure
               Hydrogen supplied to the Coker Company each month. The monthly
               Power Charge is composed of a Capacity Charge, an operations and
               maintenance charge (O&M Charge), and a Fuel Charge as follows:

               Pc\\n\\ = (CC + OM\\n\\)* ACF\\n\\ / 0.95 * TKWH\\n\\ /
                         GKWH\\n\\ + FC\\n\\ * (TKWH\\n\\ -FALKWH\\n\\)

               Where:

               Pc\\n\\ =      The Power Charge for billing month n.
               CC =           The monthly Capacity Charge of $321,333.
               Om\\n\\ =      The O&M Charge as calculated pursuant to Section
                              5.1.3 for billing month n.
               ACF\\n\\ =     The Average Capacity Factor calculated on a
                              rolling average basis for the most recent 36 month
                              period, including the current billing month n, or
                              for the actual number of billing months since the
                              Commencement Date, in accordance to Section 5.1.1.

                                      -6-
<PAGE>

                                                                    Schedule 4.4
                                                   Services and Supply Agreement

               TKWH\\n\\ =    The total KWH consumed by Air Products' 4.16 kV
                              loads as measured at the Air Products' 4.16 kV
                              switchgear for all hourly periods in billing month
                              n including those hourly periods when generator
                              CG-500 is not operating.
               Fc\\n\\ =      The Fuel Charge as calculated pursuant to Section
                              5.1.4 for billing month n.
               GKWH\\n\\ =    The gross KWH delivered by Air Products at the
                              Generator Terminal during billing month n.
               FALKWH\\n\\ =  The total KWH consumed by Air Products' Facility
                              Auxiliary Load as determined in accordance with
                              Section 5.1.2 during billing month n.

               Commencement Date shall have the meaning given such term in
               Section 2.1 of the Hydrogen Supply Agreement.

               Generator Terminal shall mean Air Products' KW and KWH metering
               point located in Air Products' 13.8 kV switchgear for Air
               Products' gas turbine generator where the gross output of the gas
               turbine generator unit is measured.

               4.5.2   Average Capacity Factor

               The Average Capacity Factor shall be calculated at the end of
               each billing month as follows:

               ACF\\n\\ = ((GKWH\\n\\ - (FALKWH\\n\\) / (Committed
                          Capacity- Facility Auxiliary Load) / (BMH

               Where:

                      [GKWH\\n\\ =  The cumulative sum of GKWH\\n\\ delivered by
                                    Air Products for the most recent 36 billing
                                    month period, including the current billing
                                    month n, or for the actual number of billing
                                    months since the Commencement Date if less
                                    than 36 billing months have elapsed since
                                    the Commencement Date.

              [FALKWH\\n\\=         The cumulative sum of FALKWH\\n\\ consumed
                                    by Air Products for the most recent 36
                                    billing month period, including the current
                                    billing month n, or for the actual number of
                                    billing months since the Commencement Date
                                    if less than 36 billing months have elapsed
                                    since the Commencement Date.

                      [BMH =        The sum of (1) the total number of hourly
                                    periods in the most recent 36 billing
                                    months, including the current billing

                                      -7-
<PAGE>

                                                                    Schedule 4.4
                                                   Services and Supply Agreement

                                   month n, or for the actual number of billing
                                   months since the Commencement Date if less
                                   than 36 billing months have elapsed since the
                                   Commencement Date less (2) the number of
                                   hourly periods in the above billing months
                                   when Air Products was excused from delivering
                                   power due to events of Force Majeure or Clark
                                   R&M being unable to receive power from Air
                                   Products at the Delivery Point due to
                                   maintenance, testing, or forced outages.

                   For avoidance of doubt, any partial hourly period is counted
                   as one full hourly period for purposes of this calculation.
                   Notwithstanding the foregoing, the Average Capacity Factor
                   for the first twelve billing months following the
                   Commencement Date shall be deemed to be 95 percent. Beginning
                   with the thirteenth billing month following the Commencement
                   Date and for each billing month thereafter, the actual
                   Average Capacity Factor will be calculated. In the event that
                   the actual Average Capacity Factor calculated for the first
                   twelve (12) billing months is greater or less than ninety-
                   five percent (95%), Clark R&M shall retroactively adjust the
                   Power Charge payments Clark R&M received for the first twelve
                   (12) billing months.

               4.5.3     Monthly Facility Auxiliary Load

               The Facility Auxiliary Load shall include all load connected to
               Air Products' 4.16 KV electrical distribution system except for
               the electric load associated with (i) Air Products' two hydrogen
               compressors (CM-250A and CM-250B), (ii) Air Products' spill gas
               compressor (CM-255), and (iii) a fixed allowance of 32 KW per
               hour for all auxiliary loads required to operate Air Products'
               two hydrogen compressors and spill gas compressor. The KWH
               consumed by the Facility Auxiliary Load each billing month is
               calculated as follows:

               FALKWH\\n\\ =  TKWH\\n\\ - (CAKWH\\n\\ + CBKWH\\n\\ + SGKWH\\n\\
                              + (32 KW * ABMH\\n\\))

               Where:

               FALKWH\\n\\ =  The total KWH consumed by the Facility Auxiliary
                              Load for billing month n.

               TKWH\\n\\ =    The total KWH consumed by Air Products' 4.16 KV
                              loads as measured at the Air Products' 4.16 KV
                              switchgear for all hourly periods in billing month
                              n excluding those hourly periods when generator
                              CG-500 is not operating.

               CAKWH\\n\\ =  The total KWH consumed by Air Products' product
                              hydrogen compressor, plant load CM-250A, for all
                              hourly periods in billing

                                      -8-
<PAGE>

                                                                    Schedule 4.4
                                                   Services and Supply Agreement

                              month n excluding those hourly periods when
                              generator CG-500 is not operating.

               CBKWH\\n\\  =  The total KWH consumed by Air Products' product
                              hydrogen compressor, plant load CM-250B, for all
                              hourly periods in billing month n excluding those
                              hourly periods when generator CG-500 is not
                              operating.

               SGKWH\\n\\  =  The total KWH consumed by Air Products' spill gas
                              compressor, plant load CM-255for all hourly
                              periods in billing month n excluding those hourly
                              periods when generator CG-500 is not operating.

               ABMH\\n\\  =   The adjusted number of hourly periods in billing
                              month n excluding those hourly periods when
                              generator CG-500 is not operating.

               Initially, the Facility Auxiliary Load is deemed to be 950 KW.

               4.5.4     O&M Charge

               The O&M Charge shall be adjusted each month after the
               Commencement Date and for the duration of this contract in
               accordance with the following formula:

               Om\\n\\ = OM\\0\\ x [0.16 x LI\\n\\/LI\\c\\ + .16 x P\\n\\/P\\c\\
               + .34 x L\\n\\/L\\c\\ + .34 x PPI\\n\\/PPI\\c\\]]

               Where:

               Om\\n\\   =    O&M Charge for billing month n
               OM\\0\\   =    $207,333/mo.
               Li\\n\\   =    Labor Index for billing month n
               Li\\c\\   =    Labor Index at the Commencement Date
               P\\n\\    =    Parts Index for billing month n
               P\\c\\    =    Parts Index for August 1998
               PPI\\n\\  =    PPI for billing month n.
               PPI\\c\\  =    PPI at the Commencement Date
               L\\n\\    =    Employment Cost  Index for billing month n.
               L\\c\\    =    Employment Cost  Index at the Commencement Date.

               4.5.5     Fuel Charge

               The Fuel Charge shall be adjusted each month after the
               Commencement Date and for the duration of this contract based on
               the average cost of natural gas consumed by the Facility in
               accordance with the following formula:

                                      -9-
<PAGE>

                                                                    Schedule 4.4
                                                   Services and Supply Agreement

            Fc\\n\\ =    FC\\0\\ x (NG\\n\\/NG\\0\\)

            Where:

            Fc\\n\\    =          Fuel Charge for billing month n
            FC\\0\\    =          $0.0074/KWH
            Ng\\n\\    =          Average cost of natural gas for the Facility
                                  in billing month n
            NG\\0\\    =          $2.25/MMBTU

            "Facility" shall mean the designed, fabricated, and installed
            equipment necessary for Air Products to manufacture hydrogen for the
            Coker Company on a leased site as described in the Clark Hydrogen
            Supply Agreement.

            4.5.6   Power Credits

            To the extent Air Products consumes electric power for compression
            of hydrogen supplied into the Pipeline Network, Clark R&M shall
            credit the Coker Company for such power, whether such power was
            produced by Air Products or, during periods of gas turbine generator
            shutdown, provided by Clark R&M to Air Products.  The credit shall
            be calculated monthly on the basis of a specific power in KWH/MSCF,
            for hydrogen compression, in accordance with the following:

            Pipeline hydrogen compression credit =  1.184 KWH/MSCF x MSCF\\n\\ x
                                                    CPC\\n\\

            Where:

            MSCF\\n\\ =  Quantity of hydrogen in MSCF compressed and supplied
                         into the Pipeline Network for billing month n.

            CPC\\n\\  =  Cost of power in $/KWH for billing month n; if supplied
                         by Air Products, to be based PC\\n\\ divided by the sum
                         of GKWH\\n\\ minus FALKWH\\n\\, or if supplied by Clark
                         R&M, Clark R&M's incremental cost for power for each
                         billing day.

            "Pipeline Network" shall mean the pipeline system connected to the
            Facility and constructed, owned, or operated by Air Products or its
            affiliates, which is used to transport hydrogen in Texas.

       4.6.   Taxes.
              ------

              The Coker Company shall reimburse Clark R&M for payments made by
              Clark R&M to Air Products for taxes, charges and fees pursuant to
              Section 12 of the Clark Hydrogen Supply Agreement.

                                     -10-
<PAGE>

                                                                    Schedule 5.1
                                                   Services and Supply Agreement

                        CONSTRUCTION MANAGEMENT SERVICES

1.   Scope.
     -----

     In accordance with its obligations under Section 5.1 of the Services and
     Supply Agreement, Clark R&M shall administer the EPC Contract on behalf of
     the Coker Company and otherwise perform (or ensure that Coker Company
     employees perform) the Coker Company's obligations (other than payment
     obligations) and exercise its rights thereunder including, without
     limitation, the following:

          a.   performing Start-up (as defined in the EPC Contract)
               activities

          b.   supporting Start-up and performance testing under the EPC
               Contract by making available and operating all testing and
               laboratory equipment, tools, machinery and vehicles (including
               trucks, mobile cranes, loaders, forklifts and other rolling
               stock) necessary for normal operation of the Coker Complex

          c.   providing water and temporary utilities, at such times and in
               such quantities as required for Contractor's prosecution of the
               EPC Contract

          d.   providing Contractor with initial drafts of the Operating Manuals
               (as defined in the EPC Contract) for the Coker Complex

          e.   performing the Coker Company's obligations with respect to spare
               parts under Section 2.38 of the EPC Contract

          f.   reviewing and approving Applications for Payment (as defined in
               the EPC Contract) in cooperation with the Independent Engineer

          g.   providing operations and maintenance personnel for Start-up and
               Performance Testing (as defined in the EPC Contract)

          h.   providing all necessary feedstreams for operation of the Coker
               Complex during Start-up and Performance Testing

          i.   preparing and delivering the Start-up Protocol (as defined in the
               EPC Contract) to the Contractor and the Independent Engineer 90
               days prior to Mechanical Completion (as defined in the EPC
               Contract) and cooperating to develop a final Start-up Protocol
               prior to Mechanical Completion

          j.   reviewing and approving each Notice of Mechanical Completion,
               Notice of Coker Completion and Notice of Final Completion
               submitted by the Contractor (as each term is defined in the EPC
               Contract) together with the Independent Engineer

<PAGE>

                                                                    Schedule 5.1
                                                   Services and Supply Agreement

          k.   initiating necessary Change Orders (as defined in the EPC
               Contract) and reviewing and approving Change Orders requested by
               the Contractor

2.   Applicable Price.
     -----------------

     The Coker Company shall pay Clark R&M $2,700,000 on (i) the date (the
     "Initial Payment Date") that is the later of (y) the first anniversary of
     the Start-up Date and (z) January 1, 2002 for providing the Services
     described in this Schedule, (ii) the date that is one year after the
     Initial Payment Date and (iii) the date that is two years after the Initial
     Payment Date.

                                      -2-

<PAGE>

                                                                    Schedule 5.3
                                                   Services and Supply Agreement

                              MAINTENANCE SERVICES

1.   Scope.
     -----

     1.1  Routine Repair and Preventative Maintenance

          Clark R&M shall provide (or engage third party subcontractors to
          provide) all repair and preventative maintenance (including necessary
          materials and labor) of a regular nature that must be performed
          periodically and on an ongoing basis to maintain the Heavy Oil
          Processing Facility including, without limitation, the services
          described below.

          a.   Cleaning Slab Services

               Removal of equipment from processing units for cleaning at Clark
               R&M-owned cleaning slabs at the Refinery including (i) removing
               such equipment from its unit, (i) draining it of all free
               liquids, (iii) transporting it to a Clark R&M cleaning slab, (iv)
               cleaning it so that acidic or caustic substances are neutralized,
               flammable or explosive substances are eliminated and hydrocarbon
               sludges or other hazardous materials are removed and the
               equipment is otherwise thoroughly clean, (iv) disposing of the
               resulting waste in accordance with Applicable Law and (v) re-
               installing such equipment into its unit.

          b.   Shop Services

               Repair and maintenance work performed by (i) Clark R&M employees
               at one of the various Clark R&M-owned and operated maintenance
               shops located at the Refinery including, without limitation,
               Clark R&M's central shop, machine shop, instrument/electrical
               shop and sandblasting/cleaning shop, or (ii) third party
               subcontractors at maintenance shops located outside the Refinery.

          c.   Maintenance Supervision

               Supervision of maintenance personnel for the Coker Company
               including, (i) monitoring operations and working with the
               operations personnel described on Schedule 5.8.1 to plan,
               schedule, and set maintenance priorities, (ii) assisting in the
               development and execution of preventative and predictive
               maintenance practices, (iii) supervising maintenance mechanics on
               a daily basis including oversight of the maintenance resource
               pool of electricians, machinists, pipefitters, welders,
               boilermakers and other crafts.

          d.   Fixed Equipment Analysis
<PAGE>

                                                                    Schedule 5.3
                                                   Services and Supply Agreement

               Monitoring, collecting data regarding and documenting the
               condition of the Heavy Oil Processing Facility's stationary
               equipment (including piping, vessels, and structural steel)
               including, without limitation (i) maintaining an inspection
               database of information, (ii) reviewing such data, (iii)
               developing recommendations for equipment repair and improvement
               and (iv) inspecting on-going repairs to assure applicable
               industry standards are followed.

          e.   Rotating Equipment Analysis

               Monitoring and improving the performance of each unit's rotating
               equipment to assure reliability and uptime of rotating equipment,
               including, without limitation, (i) routinely perform data
               collection of vibration and operational performance, (ii)
               analyzing such data, and (iii) making recommendations for repair
               and improvements.

          f.   DCS Technology Support

               Maintenance of the Coker Company's distributed control equipment
               including, without limitation, (i) interacting with unit
               operators to generate and tune simple control loops and (ii)
               working with the Clark R&M control engineers in maintaining and
               improving the overall performance of the Heavy Oil Processing
               Facility's process control systems.

         g.    Rolling Stock Services

               Provision of tractors, trucks, frontloaders, cherry pickers,
               exchange pickers or other vehicles necessary for performing the
               maintenance services described in this Schedule.

     1.2  Maintenance Turnarounds, Unit Shutdowns and Other Capital Maintenance

          a.   As part of the Annual Budget and Operating Plan, Clark R&M shall
               provide the Coker Company with a schedule of planned maintenance
               shutdowns in the next Operating Year for any unit comprising the
               Heavy Oil Processing Facility.

          b.   Clark R&M shall assess the on-going need for additional unplanned
               maintenance shutdowns and capital maintenance of units comprising
               the Heavy Oil Processing Facility.

          c.   Clark R&M shall perform (or engage third party subcontractors to
               perform) all scheduled and unscheduled maintenance shutdowns and
               other capital maintenance of the Heavy Oil Processing Facility.

     1.3  Janitorial and Grounds Services

                                      -2-
<PAGE>

                                                                    Schedule 5.3
                                                   Services and Supply Agreement

          a.  Clark R&M shall provide (or engage third party subcontractors to
              provide) all janitorial type services at the Heavy Oil Processing
              Facility

          b.  Clark R&M shall maintain (or engage third party subcontractors to
              maintain) all grounds, yards and roads located on the Coker
              Complex Site and the Ancillary Equipment Site.

2.   Applicable Price.
     ----------------

     2.1  Coker Complex

          a.   The Coker Company shall reimburse Clark R&M for the direct costs
               of all materials and other supplies and all subcontract labor or
               services necessary for performance of the maintenance services
               described herein each month for the Coker Complex and the Coker
               Complex Site.

          b.   The Coker Company shall reimburse Clark R&M for the Labor Cost of
               all hourly Clark R&M maintenance personnel necessary for the
               performance of maintenance services described herein each month
               for the Coker Complex and the Coker Complex Site. For the purpose
               of this Schedule Labor Costs shall be deemed to equal a rate per
               hour equal to (i) for any month prior to and including December
               2000, $36.00 and (ii) for any other month, $36.00, multiplied by
                                                                  -------------
               the Inflation Factor.

          c.   For all supervisory and management services provided by Clark R&M
               related to maintenance services for the Coker Complex described
               herein each month, the Coker Company shall pay Clark R&M (i) for
               any month after the Start-up Date and prior to and including
               December 2000, $62,500.00 and (ii) for any month thereafter,
               $62,500.00, multiplied by the Inflation Factor.
                           -------------

     2.2  Ancillary Equipment

          Consideration for maintenance services provided by Clark R&M to the
          Coker Company related to the Ancillary Equipment and the Ancillary
          Equipment Site is included in the Ancillary Equipment Operating Fee,
          except to the extent that Clark R&M is required to perform capital
          maintenance with respect to the Ancillary Equipment in order to comply
          with a change in Applicable Law. In such case, the Coker Company shall
          pay Clark R&M for its share of all Permitted Reimbursable Expenses
          incurred by Clark R&M in performing all such unscheduled capital
          maintenance related to the Ancillary Equipment. The Coker Company's
          share of such Permitted Reimbursable Expenses shall be determined in
          accordance with Section 7.4(a) of the Services and Supply Agreement.

                                      -3-
<PAGE>

                                                                  Schedule 5.5.1
                                                   Services and Supply Agreement

                              ELECTRICITY SERVICES

13.  Scope.
     -----

     a.   Coker Complex

          Supply of electric energy requirements of the Coker Company for use at
          the Coker Complex.

     b.   Ancillary Equipment

          Supply of electric energy requirements of the Coker Company for use
          at the Ancillary Equipment.

14.  Metering/Measurement Methodology for Services to the Coker Complex.
     ------------------------------------------------------------------

     3.   2.1  The following meters to be installed pursuant to the EPC Contract
               shall be used to measure the number of kilowatt (1000 watts)
               hours ("KWH") of electricity that are delivered to each distinct
               area of the Coker Complex:

      i.  Main power station number 6

          Meters located at:

          a.  Air Products Steam Methane Reformer
          b.  Gulf States #1 transformer
          c.  Gulf States #2 transformer

     ii.  DCU 843 Coker area main facilities.

          Switch Gear -- 843-SG-01

     iii. HCU 942 Hydrocracker/SRU 545 Sulfur Plant/SWS 8747 Sour Water
          Stripper/ATU 7814 Amine Treating Unit

          Switch Gear -- 942-SG-01

     iv.  Coker feed charge-pumps for tanks 108 and 109 and the Coker Complex
          cooling tower

          Substation 261

     5.   Flare No. 23 and other offsites
<PAGE>

                                                                  Schedule 5.5.1
                                                   Services and Supply Agreement

             Electricity delivered to flare no. 23 and other offsites comprising
             the Coker Complex and not described above shall be measured by
             subtracting metered usage in numbers 2 through 4 above from metered
             usage in number 1 above.

     2.2  Clark R&M shall read the Coker Complex meters described in 2.1 above
          to determine the total KWH usage of the Coker Complex for each month
          (the "Monthly Coker Complex Electricity Usage"); provided, however,
                                                           --------  -------
          that at any time when such meters are not functioning the Monthly
          Coker Complex Electricity Usage shall be determined (a) for any month
          prior to three full calendar months after Final Completion, based on
          the "typical" or expected usages described in the following chart, or
          (b) for any other month, based on the average Monthly Coker Complex
          Electricity Usage for the prior three calendar months.

--------------------------------------------------------------------------------
Electrical Produced (Consumed), KWSD (68 oF)
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
     Consumption
--------------------------------------------------------------------------------
     COKER COMPANY UNITS                Typical Quantity   Per Cent Usage
--------------------------------------------------------------------------------
     SRU 545                                (2,128)             2.09
--------------------------------------------------------------------------------
     DCU 843                                (20,550)            20.20
--------------------------------------------------------------------------------
     HCU 942                                (13,326)            13.10
--------------------------------------------------------------------------------
     ATU 7841                                (223)              0.22
--------------------------------------------------------------------------------
     SWS 8747                                (194)              0.19
--------------------------------------------------------------------------------
     Sour Water Tank 78                      (154)              0.15
--------------------------------------------------------------------------------
     C.T. 432                                (602)              0.59
--------------------------------------------------------------------------------
     FLARE 23                                 (50)              0.05
--------------------------------------------------------------------------------
     Resid Tanks 108/109                     (999)              0.98
--------------------------------------------------------------------------------
       Sub Total                            (38,226)            37.57
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
ANCILLARY EQUIPMENT UNITS
--------------------------------------------------------------------------------
    AVU 146                                 (6,154)             6.05
--------------------------------------------------------------------------------
    GFU 242                                  (731)              0.72
--------------------------------------------------------------------------------
    GFU 243                                 (2,007)             1.97
--------------------------------------------------------------------------------
    Cooling Tower 136--SMR                   (200)              0.20
--------------------------------------------------------------------------------
    NHT 1344                                 (715)              0.70
--------------------------------------------------------------------------------
    Pump House 41                            (559)              0.55
--------------------------------------------------------------------------------
    Offsites--P.S. and B.H.'s               (6,593)             6.48
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
       Sub Total                            (16,959)            16.67
--------------------------------------------------------------------------------

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

                                      -5-
<PAGE>

--------------------------------------------------------------------------------
OTHER CLARK UNITS
--------------------------------------------------------------------------------
    GFU 241                                  (971)              0.95
--------------------------------------------------------------------------------
    GFU 244                                 (3,506)             3.45
--------------------------------------------------------------------------------
    HFAU 443                                (1,205)             1.18
--------------------------------------------------------------------------------
    SRU 543/544                             (2,380)             2.34
--------------------------------------------------------------------------------
    FCCU 1241                               (2,246)             2.21
--------------------------------------------------------------------------------
    CRU 1344                                (7,499)             7.37
--------------------------------------------------------------------------------
    SGRU 1242                               (1,483)             1.46
--------------------------------------------------------------------------------
    Offsites                                (11,315)            11.12
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
       Clark Sub Total                      (30,604)            30.08
--------------------------------------------------------------------------------

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

--------------------------------------------------------------------------------
Coker Company Plus Clark R&M                (85,789)            84.32
 Sub Total
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
CHEVRON CCC/PADC                            (5,781)             5.68
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
       Refinery Plus CCC Sub Total          (91,570)            90.00
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
HT PSA Off Gas                               (920)              0.90
--------------------------------------------------------------------------------
AIR PRODUCTS                                (9,255)             9.10
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
       Total Facility Consumption          (101,745)           100.00
--------------------------------------------------------------------------------

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

--------------------------------------------------------------------------------
     Production or Purchases
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
CLARK R&M GENERATORS                        43,498            42.75
--------------------------------------------------------------------------------
AIR PRODUCTS                                40,200            39.51
--------------------------------------------------------------------------------
PURCHASED--ENTERGY                          18,047            17.74
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
       Total Production or Purchased       101,745           100.00
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
Net                                                            0
--------------------------------------------------------------------------------

                                      -6-
<PAGE>

                                                                  Schedule 5.5.1
                                                   Services and Supply Agreement

15.  Applicable Price.
     ----------------

     a.   Coker Complex

          The Coker Company shall pay Clark R&M for the actual cost of providing
          electric energy services to the Coker Complex each month based on the
          following formula:

              (KWH Price  * Monthly Coker Complex Electricity Usage) +
              Incremental Demand Charge

     Where:

              "KWH Price" means, for any month, the price per KWH charged Clark
              R&M for electricity provided to Clark R&M by Air Products, Inc. in
              such month.

              "Incremental Demand Charge" means, for any month, the difference
              between (i) the demand charge for standby electricity services
              provided to Clark R&M by Entergy Corp. for use at the Refinery in
              such month, less (ii) the average monthly demand charge for
                          ----
              standby electricity services provided to Clark R&M by Entergy
              Corp. for use at the Refinery for one year period prior the date
              hereof.

     b.       Ancillary Equipment

              Consideration for electric energy provided by Clark R&M to the
              Coker Company for use at the Ancillary Equipment is included in
              the Ancillary Equipment Operating Fee.

     Required Billing Information.
     ----------------------------

     Clark R&M shall provide the following information as an attachment to its
     monthly Reconciliation Statements:

     a.   Total KWH measured through each Coker Complex meter.

     b.   Calculation of the Incremental Demand Charge and current KWH Price

     c.   Total amount due from Coker Company for electric energy provided to
          the Coker Complex

                                      -7-
<PAGE>

                                                                  Schedule 5.5.2
                                                   Services and Supply Agreement

                                STEAM SERVICES

1.   Scope.
     -----

     a.   Clark R&M shall supply the full steam requirements of the Coker
          Company for use at the Heavy Oil Processing Facility. Such steam is
          expected to have the typical properties and specifications set forth
          in the Turnkey Specifications and the chart in 2.2 below.

     b.   Clark R&M shall take delivery of all excess steam not consumed during
          operation of the Heavy Oil Processing Facility and route such steam to
          other units at the Refinery.

     c.   Metering/Measurement Methodology for Services to the Coker Complex.
          ------------------------------------------------------------------

     a.   Meters to be installed pursuant to the EPC Contract and described on
          Schedule 5.5(b) shall be used to measure the number of pounds per hour
          of actual steam that are delivered to the Coker Complex and returned
          to Clark R&M which will then be converted to pounds of Standard Steam
          ("MLBS SS"). "Standard Steam" is a measure used to express the value
          of steam of differing temperatures and pressures in a uniform way. It
          shall be determined by multiplying the pounds of actual steam supplied
          by the standard steam factor for the relevant poundage as described
          below under 5.

     2.2  Clark R&M shall read the applicable Coker Complex meters described on
          Schedule 5.5(b) on the last day of every month to determine the total
          pounds of actual steam usage of the Coker Complex for such month and
          convert such poundage to MLBS SS  (the "Monthly Coker Complex Steam
          Usage") and the total actual pounds of steam returned to Clark R&M
          from the Coker Complex in such month and convert such poundage to MLBS
          SS (the "Monthly Coker Complex Return Steam"); provided, however, that
                                                         --------  -------
          at any time when such meters are not functioning the Monthly Coker
          Complex Steam Usage shall be determined (a) for any month prior to
          three full calendar months after Final Completion, based on the
          "typical" or expected usages described in the following chart, or (b)
          for any other month, based on the average Monthly Coker Complex Steam
          Usage for the prior three calendar months.
<PAGE>

                                                                  Schedule 5.5.2
                                                   Services and Supply Agreement

<TABLE>
<CAPTION>

Steam Produced (Consumed), M Pounds/Hour
----------------------------------------

-----------------------------------------------------------------------------------------------------------------------------------
COKER COMPLEX UNITS          850     650 PSIG, 500 PSIG, 225 PSIG,  170 PSIG, 125 PSIG,  50 PSIG,   15 PSIG,  Net Mlbs of  Percent
                             PSIG,    Actual    Actual    Actual    Actual    Actual     Actual     Actual     SS/hour     Usage
-----------------------------------------------------------------------------------------------------------------------------------
<S>                          <C>     <C>       <C>       <C>        <C>       <C>        <C>        <C>       <C>          <C>
    SRU 545                           115.8                                    (25.4)      76.3       (2.0)      182.6
-----------------------------------------------------------------------------------------------------------------------------------
    DCU 843                          (130.1)                                    21.1                            (149.8)
-----------------------------------------------------------------------------------------------------------------------------------
    HCU 942                             2.5                                     (9.6)                             (5.5)
-----------------------------------------------------------------------------------------------------------------------------------
    ATU 7841                                                                              (63.4)
-----------------------------------------------------------------------------------------------------------------------------------
    SWS 8747                                                                              (53.8)
-----------------------------------------------------------------------------------------------------------------------------------
    C.T. 432                                                                   (41.4)      41.4
-----------------------------------------------------------------------------------------------------------------------------------
    FLARE 23                                                                    (1.0)
-----------------------------------------------------------------------------------------------------------------------------------
    OFFSITES                                                                               74.8                   55.4
-----------------------------------------------------------------------------------------------------------------------------------
       Sub Total                      (11.8)                                   (56.3)      75.3       (2.0)      (12.2)     (0.4%)
-----------------------------------------------------------------------------------------------------------------------------------
                  ANCILLARY UNITS
-----------------------------------------------------------------------------------------------------------------------------------
    AVU 146                                       (207.0)                     (137.2)     (11.7)      23.9      (378.7)
-----------------------------------------------------------------------------------------------------------------------------------
    GFU 242                           (21.0)                                   (43.0)     (21.0)                 (82.2)
-----------------------------------------------------------------------------------------------------------------------------------
    GFU 243                           (54.2)                                   (93.6)                 14.8      (147.3)
-----------------------------------------------------------------------------------------------------------------------------------
    SGRU 1242                        (117.7)                                  (127.8)     (35.5)      82.1      (247.3)
-----------------------------------------------------------------------------------------------------------------------------------
    Offsites                                                                   (30.0)                            (27.5)
-----------------------------------------------------------------------------------------------------------------------------------
       Sub Total                      (192.9)     (207.0)                     (431.6)     (68.2)     120.8      (883.0)    (27.6%)
-----------------------------------------------------------------------------------------------------------------------------------
Clark R&M UNITS
-----------------------------------------------------------------------------------------------------------------------------------
    GFU 241                            (18.2)                                                                    (23.7)
-----------------------------------------------------------------------------------------------------------------------------------
    GRU 244                           (300.2)                        49.0       61.4                            (285.8)
-----------------------------------------------------------------------------------------------------------------------------------
    HFAU 443                           (19.9)                                  (77.8)               (168.9)     (197.7)
-----------------------------------------------------------------------------------------------------------------------------------
    SRU 543/544                                   139.0                       (201.9)     (34.0)      29.0       (18.9)
-----------------------------------------------------------------------------------------------------------------------------------
    FCCU 1241                         (687.9)    (399.0)                       465.1                 133.8      (887.7)
-----------------------------------------------------------------------------------------------------------------------------------
    CRU 1344                            90.1                                   (63.7)                  0.1        58.9
-----------------------------------------------------------------------------------------------------------------------------------
    Offsites                                                                   (30.0)
-----------------------------------------------------------------------------------------------------------------------------------
       Sub Total                      (936.1)     (260.0)            49.0      153.1      (34.0)      (6.0)   (1,382.3)    (43.2%)
-----------------------------------------------------------------------------------------------------------------------------------
Clark R&M BOILERS              768.0   790.0                          3.0        3.0                 (31.0)    2,137.8
-----------------------------------------------------------------------------------------------------------------------------------
       Clark R&M Sub Total     768.0  (339.0)     (467.0)     0.0    52.0     (275.5)    (102.2)      83.8      (127.5)
-----------------------------------------------------------------------------------------------------------------------------------
       Coker Company Plus      768.0  (350.8)     (467.0)     0.0    52.0     (331.8)     (26.9)      81.8      (139.7)
-----------------------------------------------------------------------------------------------------------------------------------
       Clark R&M Sub Tiak
-----------------------------------------------------------------------------------------------------------------------------------
CHEVRON CCC/PADC              (768.0) (114.0)       (8.0)                     (252.0)                (24.0)   (1,526.7)   (47.7%)
-----------------------------------------------------------------------------------------------------------------------------------
       Refinery Plus CCC
                Sub Total        0.0  (464.8)     (475.0)     0.0    52.0     (583.8)     (26.9)      57.8    (1,666.4)
-----------------------------------------------------------------------------------------------------------------------------------
DESTEC                                 388.0                                                                     504.4
       Destec + Refinery +
       CCC Sub Total             0.0   (76.8)     (475.0)     0.0    52.0     (583.8)     (26.9)      57.8    (1,162.0)
-----------------------------------------------------------------------------------------------------------------------------------
AIR PRODUCTS                           443.5                                   (23.0)                            555.5
-----------------------------------------------------------------------------------------------------------------------------------
       Total                     0.0   366.7      (475.0)     0.0    52.0     (606.8)     (26.9)      57.8       (12.7)   (0.4%)
------------------------------------------------------------------------------------------------------------------------------------
                                                                                                       Net Producers of  100.0%
                                                                                                                         -----------
</TABLE>

3.   Applicable Price.
     ----------------

     a.     Coker Complex

     The Coker Company shall pay Clark R&M for the actual cost of providing
     steam services to the Coker Complex each month based on the following
     formula:

          Average Monthly Refinery Steam Cost * (Monthly Coker Complex Steam
          Usage - Monthly Coker Complex Return Steam).

     Where:

     "Average Monthly Refinery Steam Cost" means for any month, (a) the total
     costs in dollars incurred by Clark R&M for the purchase, production and
     distribution of

                                      -2-
<PAGE>

                                                                  Schedule 5.5.2
                                                   Services and Supply Agreement

          steam at the Refinery during such month, divided by (b) the Total MLBS
                                                   ----------
          SS Distributed during such month.

          "Total MLBS SS Distributed" means the total MLBS SS of steam
          distributed between Clark R&M, affiliates of Clark R&M, Chevron
          Chemical Company and affiliates of Chevron Chemical Company at the
          Refinery and the adjacent facilities owned by Chevron Chemical Company
          or the affiliates thereof.

     b.   Ancillary Equipment

          Consideration for steam services provided by Clark R&M to the Coker
          Company for use at the Ancillary Equipment is included in the
          Ancillary Equipment Operating Fee.

4.   Required Billing Information.
     ----------------------------

     Clark R&M shall provide the following information as an attachment to its
     monthly Reconciliation Statements:

     a.   Total actual steam measured through each Coker Complex meter described
          above and conversion of such poundage to MLBS SS.

     b.   Calculation of the Average Monthly Refinery Steam Cost and the Total
          MLBS SS Distributed

     c.   Total amount due from Coker Company for steam services provided to the
          Coker Complex

5.   Additional Terms.
     ----------------

     5.1  Standard Steam Conversion Factors
          ---------------------------------

          To convert steam to Standard Steam, the number of pounds of actual
          steam shall be multiplied by the relevant standard steam factor.

                                      -3-

<PAGE>

                                                                  Schedule 5.5.2
                                                   Services and Supply Agreement

<TABLE>
<CAPTION>
               Poundage of Steam    Standard Steam Factor
               -----------------    ---------------------
               <S>                  <C>
                      850                  1.463
                      650                    1.3
                      500                   1.25
                      225                  1.098
                      170                  0.986
                      125                  0.915
                       50                  0.741
                       15                  0.596
</TABLE>

          5.2  Standard Steam Definition
               -------------------------

               The steam accounting system at the Refinery is based on energy
               content. All actual pounds of steam are converted to Standard
               Steam. All costs (from the appropriate cost centers in Clark
               R&M's accounting system) in producing steam are then divided by
               the pounds of Standard Steam.

               One pound of Standard Steam is defined as the steam at the
               conditions whereby ten pounds of steam generate 1 KWH of
               electricity at 100% efficiency when exhausted through a turbine
               to a pressure of 2.5" mercury absolute.

               The Standard Steam conversion factors are then calculated as
               illustrated in the following example.

                      (1)  850 PSIG, 800F steam at 100% efficiency requires
                           6.837 pounds of actual steam to generate a KWH of
                           electricity

                      (2)  The Standard Steam factor equals 10 (the theoretical
                           steam rate of Standard Steam) divided by 6.837 (the
                           theoretical steam rate of 850 PSIG, 800F steam), or
                           1.463.

               This means 100,000 pounds of 850 PSIG, 800F steam would equal
               146,300 pounds of Standard Steam.

               The energy basis for Standard Steam factors can be calculated by
               the following formula:

                      Standard Steam Factor (energy basis) =

                         Ha - 568.409 Ea + 5.777
                         -----------------------
                               341.275
                      Where:
                      Ha = Enthalpy of actual steam (BTUs/lb)

                                      -4-

<PAGE>

                                                                  Schedule 5.5.2
                                                   Services and Supply Agreement

                      Ea = Entropy of actual steam (BTUs/lb F)

               The basis for this formula is that enthalpy versus entropy for
               steam-water mixture at 2.5" mercury absolute is a straight line
               for values of entropy of 1.34 to 1.96 BTUs/lb F.

                                      -5-

<PAGE>

                                                                  Schedule 5.5.3
                                                   Services and Supply Agreement

                         NATURAL AND FUEL GAS SERVICES

1.   Scope.
     -----

     a.   Clark R&M shall supply the natural gas and fuel gas requirements of
          the Coker Company for use at the Heavy Oil Processing Facility. Such
          natural gas and fuel gas is expected to have the typical properties
          and specifications set forth in the Turnkey Specifications and the
          charts in 2 below.

     1.2  Clark R&M shall take delivery of all natural gas and fuel gas not
          consumed during operation of the Heavy Oil Processing Facility.

     1.3  The Coker Company shall pay Clark R&M for the amount of natural gas
          and fuel gas consumed by each unit of the Heavy Oil Processing
          Facility and not returned to Clark R&M.

     1.4  Pursuant to the Product Purchase Agreement, Clark R&M is purchasing
          the fuel gas produced during operation of the units comprising the
          Heavy Oil Processing Facility net of fuel gas supplied to such units.

2.   Metering/Measurement Methodology for Services to the Coker Complex.
     ------------------------------------------------------------------

     a.   Monthly Natural Gas Consumption

          Meters to be installed pursuant to the EPC Contract and described on
          Schedule 5.5(b) shall be used to measure the millions of British
          thermal units ("MMBTUs") of natural gas that are delivered to and
          consumed by the Coker Complex each month ("Monthly Natural Gas
          Consumption"); provided, however, that at any time when such meters
                         --------  -------
          are not functioning the Monthly Coker Natural Gas Consumption Usage
          shall be determined (a) for any month prior to three full calendar
          months after Final Completion, based on the "typical" or expected
          usages described in the following chart, or (b) for any other month,
          based on the average Monthly Natural Gas Consumption for the prior
          three calendar months.

<PAGE>

                                                                  Schedule 5.5.3
                                                   Services and Supply Agreement

Consumed, MMBTU's/Hr.--HHV
--------------------------

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------------------------
 Process Description                                            Typical Volume                  Percent Usage
-------------------------------------------------------------------------------------------------------------
<S>                                                             <C>                             <C>
COKER COMPLEX UNITS

    SRU 545                                                          77.5

    DCU 843                                                          37.1

    HCU 942                                                           7.8

    ATU 7841                                                            0

    SWS 8747                                                            0

    C.T. 432                                                            0

    FLARE 23                                                         0.19

    DCU 843 Charge Tanks                                             0.01

          Sub Total                                                   123                                2.6%

ANCILLARY EQUIPMENT UNITS

    AVU 146                                                            66

    GFU 242                                                          61.9

    GFU 243                                                           3.3

    SGRU 1242                                                         7.3

    PRORATED, NG to Mix Drum                                          557

         Sub Total                                                    696                               14.7%

Clark R&M UNITS

    GFU 241                                                          42.4

    GFU 244                                                          15.0

    HFAU 443                                                         42.0

    SRU 543/4                                                        62.2

    FCCU 1241                                                        36.0

    CRU 1344                                                         17.0

    Miscellaneous                                                    13.0

    PRORATED, NG to Mix Drum                                        613.6

    Reduced consumption                                             (75.0)

         Sub Total                                                  766.2                               16.2%

Clark R&M BOILERS                                                     706                               14.9%

         Clark R&M Sub Total                                      2,168.1

         Coker Complex Plus Clark R&M Sub Total                      2291

CHEVRON CCC/PADC                                                      295                                6.2%

        Refinery Plus CCC Sub Total                               2,585.7

AIR PRODUCTS                                                      2,156.0                               45.5%

        Total                                                     4,741.7                              100.0%
</TABLE>

     b.   Monthly Fuel Gas Consumption

          Meters to be installed pursuant to the EPC Contract and described on
          Schedule 5.5(b) shall be used to measure the MMBTUs of fuel gas
          delivered to and consumed by, the Coker Complex each month ("Monthly
          Fuel Gas Consumption"); provided, however,  that at any time when such
                                  --------  -------
          meters are not functioning the Monthly Fuel Gas Consumption shall be
          determined (a) for any month prior to three full calendar months after
          Final Completion, based on the "typical" or expected usages described
          in the following chart, or (b) for any other month, based on the
          average Monthly Fuel Gas Consumption for the prior three calendar
          months.

                                      -2-

<PAGE>

                                                                  Schedule 5.5.3
                                                   Services and Supply Agreement

Production (Consumption), MMBTU's/HR. (HHV)
-------------------------------------------
<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------
Process Description                                         Typical Volume                     Percent Usage
------------------------------------------------------------------------------------------------------------
<S>                                                        <C>                                <C>
COKER COMPANY UNITS

    SRU 545                                                   0.0

    DCU 843                                                 452.3

    HCU 942                                                   0.0

    ATU 7841                                                  0.0

    SWS 8747                                                  0.0

    C.T. 432                                                  0.0

    FLARE 23                                                  0.0

    DCU 843 Charge Tanks                                      0.0

    HT PSA                                                  (30.5)

        Sub Total                                           421.8                             (36.0%)

ANCILLARY EQUIPMENT UNITS

    AVU 146                                                (597.4)

    GFU 242                                                   5.8

    GFU 243                                                  83.6

    SGRU 1242                                               266.7

        Sub Total                                          (241.3)                             20.6%

Clark R&M UNITS

    GFU 241                                                  53.9

    GFU 244                                                 157.8

    HFAU 443                                                (83.4)

    FCCU 1241                                               480.3

    CRU 1344                                               (351.4)

    Reduced production                                     (129.0)
    Miscellaneous consumption                               (34.0)

        Sub Total                                            94.2                              (8.0%)

Clark R&M BOILERS                                        (1,737.0)                            148.3%

        Clark R&M Sub Total                              (1,884.1)

        Coker Company Plus Clark R&M Sub Total           (1,462.3)

CHEVRON CCC/PADC                                            519.0                             (44.3%)

        Refinery Plus CCC Sub Total                        (943.3)

AIR PRODUCTS

    Refinery Fuel to SMR                                   (228.0)                             19.5%
        Total                                            (1,171.3)                            100.0%
</TABLE>

3.          Applicable Price.
            ----------------

           a.  Coker Complex

               The Coker Company shall pay Clark R&M for the actual cost of
     providing natural gas and fuel gas services to the Coker Complex each month
     based on the following formula:

                    MMBTU Price * Monthly MMBTU Usage

               Where:

          "MMBTU Price" means, for any month the sum of (i) Gulf Coast NG for
          such month, plus (ii) $.015.
                      ----
<PAGE>

                                                                  Schedule 5.5.3
                                                   Services and Supply Agreement

               "Gulf Coast NG" means, for any month, the average Houston Ship
               Channel (Large) Quote stated in MMBTUs in Inside FERCS Gas Market
               Report (Trends in Spot Price Indicators) .

               "Monthly MMBTU Usage" means for any month the sum of (a) Monthly
                Natural Gas Consumption, and (b) Monthly Fuel Gas Consumption.

        b.     Ancillary Equipment

               Consideration for natural and fuel gas services provided by Clark
               R&M to the Coker Company for use at the Ancillary Equipment is
               included in the Ancillary Equipment Operating Fee.

   4.   Required Billing Information.
        ----------------------------

        Clark R&M shall provide the following information as an attachment to
        its monthly Reconciliation Statements:

        4.1  Total MMBTUs of natural gas and fuel gas delivered each unit of the
             Coker Complex.

        4.2  Total MMBTUs of natural gas and fuel gas produced by each unit of
             the Coker Complex.

        4.3  Calculation of the Monthly MMBTU Usage

        4.4  Gulf Coast NG

        4.5  Total amount due from Coker Company for natural gas and fuel gas
             provided to the Coker Complex

                                      -4-
<PAGE>

                                                                  Schedule 5.5.4
                                                   Services and Supply Agreement
                                WATER SERVICES.
   5.       Scope.
            -----

            a.   Supply of the Coker Company's requirements for the following
                 types of water for use at the Heavy Oil Processing Facility.

                 a.  Boiler Feedwater

                     "Boiler Feedwater" means a combination of untreated water
                     and condensed steam meeting the specifications therefor set
                     forth in the Turnkey Specifications and under the heading
                     "BFW" on the chart in 4 below.

                 b.  Filtered Water

                     "Filtered Water" means Clarified Water (as defined below)
                     that has been filtered to remove particulate matter and
                     meeting the specifications therefor set forth in the
                     Turnkey Specifications and under the heading "Filtered
                     Water" on the chart in 4 below.

                 c.  Clarified Water

                     "Clarified Water" means untreated water purchased by Clark
                     R&M from the Lower Neches Valley Authority and meeting the
                     specifications therefor set forth in the Turnkey
                     Specifications and under the heading "Clarified Water" on
                     the chart in 4 below.

                 d.  Potable Water

                     "Potable Water" means drinking water purchased by Clark R&M
                     from the City of Port Arthur.

                 e.  Fire Water

                     "Fire Water" means Clarified Water used for fire fighting
                     purposes and purchased by Clark R&M  from the City of Port
                     Arthur.

                 f.  Demineralized Water

                     "Demineralized Water" means Clarified Water that has been
                     treated to remove particulate matter and meeting the
                     specifications therefor set forth in the Turnkey
                     Specifications and under the heading "Demineralized Water"
                     on the chart in 4 below.
<PAGE>

                                                                  Schedule 5.5.4
                                                   Services and Supply Agreement

                 b.  Offtake of all condensed steam ("Condensate") from
                     operation of the Heavy Oil Processing Facility.

 6.  Metering/Measurement Methodology for Services to the Coker Complex
     ------------------------------------------------------------------

     The meters to be installed pursuant to the EPC Contract and described on
     Schedule 5.5(b) shall be used to measure the thousands of gallons ("MGALs")
     of each type of water that are delivered to the Coker Complex each month
     and the MGALs of Condensate that are produced by the Coker Company each
     month (the "Monthly Condensate MGALs"); provided, however, that at any time
                                             --------  -------
     when such meters are not functioning the Monthly Condensate MGALs shall be
     determined (a) for any month prior to three full calendar months after
     Final Completion, based on the "typical" or expected usages described in
     the chart in number 4 below, or (b) for any other month, based on the
     average Monthly Condensate MGALs for the prior three calendar months.

 7.  Applicable Price.
     ----------------

     a.  Coker Complex

         The Coker Company shall pay Clark R&M for the supply of each type of
         water described above to the Coker Complex each month according to the
         following formula:

         Boiler Feedwater Cost + Filtered Water Cost + Clarified Water
         Cost + Demineralized Water Cost - Condensate Payment.

         Where:

         a.  Boiler Feedwater Cost

             The "Boiler Feedwater Cost" each month shall be determined
             according to the following formula:

                   Average Monthly Refinery Boiler Feedwater Cost * Monthly
                   Boiler Feedwater MGALs

             Where:

             "Average Monthly Refinery Boiler Feedwater Cost" means, for any
             month, (a) the actual costs in dollars incurred by Clark R&M for
             the provision of Boiler Feedwater throughout the Refinery, divided
                                                                        -------
             by (b) the MGALs of Boiler Feedwater distributed in such month
             --
             throughout the Refinery.

                                      -2-
<PAGE>

                                                                  Schedule 5.5.4
                                                   Services and Supply Agreement

               "Monthly Boiler Feedwater MGALs" means, for any month the total
               metered MGALs of Boiler Feedwater distributed to the Coker
               Complex in such month; provided, however, that at any time when
                                      --------  -------
               such meters are not functioning the Monthly Boiler Feedwater
               MGALs shall be determined (a) for any month prior to three full
               calendar months after Final Completion, based on the "typical" or
               expected usages described in the chart in 4 below, or (b) for any
               other month, based on the average Monthly Boiler Water MGALs for
               the prior three calendar months.

         b.    Filtered Water Cost

               The "Filtered Water Cost" each month shall be determined
               according to the following formula:

               Average Monthly Refinery Filtered Water Cost * Monthly Filtered
               Water MGALs

               Where:

               "Average Monthly Refinery Filter Water Cost" means, for any
               month, (a) the actual costs in dollars incurred by Clark R&M for
               the provision of Filtered Water throughout the Refinery, divided
                                                                        -------
               by (b) the total MGALs of Filtered Water distributed in such
               --
               month throughout the Refinery.

               "Monthly Filtered Water MGALs" means, for any month the total
               metered MGALs of Filtered Water distributed to the Coker Complex
               in such month; provided, however, that at any time when such
                              --------  -------
               meters are not functioning the Monthly Filtered Water MGALs shall
               be determined (a) for any month prior to three full calendar
               months after Final Completion, based on the "typical" or expected
               usages described in the chart in 4 below, or (b) for any other
               month, based on the average Monthly Filtered Water MGALs for the
               prior three calendar months. provided, however, that at any time
                                            --------  -------
               when the applicable meters are not functioning the Monthly
               Filtered Water MGALs shall be determined based on the "typical"
               or expected usages described in the chart in 4 below.

         c.    Clarified Water Cost

               The "Clarified Feedwater Cost" each month shall be determined
               according to the following formula:

               Average Monthly Refinery Clarified Water Cost * Monthly Clarified
               Water MGALs

               Where:

                                         -3-
<PAGE>

                                                                  Schedule 5.5.4
                                                   Services and Supply Agreement

               "Average Monthly Refinery Clarified Water Cost" means, for any
               month, (a) the actual costs in dollars incurred by Clark R&M for
               the provision of Clarified Water (including Fire Water)
               throughout the Refinery, divided by (b) the total MGALs of
                                        ----------
               Clarified Water distributed in such month throughout the
               Refinery.

               "Monthly Clarified Water MGALs" means, for any month the total
                metered MGALs of Clarified Water distributed to the Coker
                Complex in such month; provided, however, that at any time when
                                       --------  -------
               such meters are not functioning the Monthly Clarified Water
               MGALs shall be determined (a) for any month prior to three full
               calendar months after Final Completion, based on the "typical"
               or expected usages described in the chart in 4 below, or (b) for
               any other month, based on the average Monthly Clarified Water
               MGALs for the prior three calendar months.

         d.    Potable Water Cost

               The cost of Potable Water provided to the Coker Company each
               month for use in connection with operation of the Coker Complex
               and the Ancillary Equipment is included in the rent payable under
               the Coker Complex Ground Lease and the Ancillary Equipment Site
               Lease, respectively.

         e.    Demineralized Water Cost

               The "Demineralized Feedwater Cost" each month shall be determined
               according to the following formula:

               Average Monthly Refinery Demineralized Water Cost * Monthly
               Demineralized Water MGALs

               Where:

               "Average Monthly Refinery Demineralized Water Cost" means, for
               any month, (a) the actual costs in dollars incurred by Clark R&M
               for the provision of Demineralized Water throughout the Refinery,
               divided by (b) the total MGALs of Demineralized Water distributed
               ----------
               in such month throughout the Refinery.

               "Monthly Demineralized Water MGALs" means, for any month the
               total metered MGALs of Demineralized Water distributed to the
               Coker Complex in such month; provided, however, that at any time
                                            --------  -------
               when such meters are non functioning the Monthly Demineralized
               Water MGALs shall be determined (a) for any month prior to three
               full calendar months after Final Completion,

                                      -4-
<PAGE>

                                                                  Schedule 5.5.4
                                                   Services and Supply Agreement

                    based on the "typical" or expected usages described in the
                    chart in 4 below, or (b) for any other month, based on the
                    average Monthly Demineralized Water MGALs for the prior
                    three calendar months.

         f.    Condensate Payment

               The "Condensate Payment" each month shall be determined according
               to the following formula:

                      Average Monthly Refinery Boiler Feedwater Cost * Monthly
                      Condensate MGALs

4.
                                      -5-

<PAGE>

                                                                  Schedule 5.5.4
                                                   Services and Supply Agreement

4.   Additional Terms.
     ----------------

<TABLE>
<CAPTION>
Water Produced (Consumed)
---------------------------
<S>                          <C>         <C>          <C>         <C>            <C>     <C>             <C>    <C>         <C>
COKER COMPLEX UNITS          Clarified   Filtered     Demin       Zeolite        BFW     Condensate      Fire   Potable     Waste
                             Water,      Water,       Water,      Water,                                 Water  Water       Water,
                             Mlbs/Hr     Mlbs/Hr.     Mlbs/Hr     Mlbs/Hr                                                    GPM
----------------------------------------------------------------------------------------------------------------------------------
    SRU 545                                            (193.0)                  (193.0)        43.2                           18.0
----------------------------------------------------------------------------------------------------------------------------------
    DCU 843                      (50.0)                                          (68.0)        63.0                           25.0
----------------------------------------------------------------------------------------------------------------------------------
    HCU 942                                                                     (146.0)       (84.0)                          25.0
----------------------------------------------------------------------------------------------------------------------------------
    ATU 7841                                                                                   63.4                           18.0
----------------------------------------------------------------------------------------------------------------------------------
    SWS 8747                                                                                   53.8                          267.0
----------------------------------------------------------------------------------------------------------------------------------
    C.T. 432                    (492.0)                                                                                       72.0
----------------------------------------------------------------------------------------------------------------------------------
    FLARE 23                                                                     (23.0)       (23.0)
----------------------------------------------------------------------------------------------------------------------------------
    OFFSITES                                                                                                                  10.0
----------------------------------------------------------------------------------------------------------------------------------
       Sub Total                (542.0)       0.0      (193.0)        0.0       (430.0)       116.4                          435.0
----------------------------------------------------------------------------------------------------------------------------------
    Percent Usage Coker Company    6.6%       0.0%      (26.9%)       0.0%        12.6%     (3325.7%)  #DIV/0!  #DIV/0!        7.4%
----------------------------------------------------------------------------------------------------------------------------------
ANCILLARY EQUIPMENT
----------------------------------------------------------------------------------------------------------------------------------
    AVU 146                                                                                   103.7                          420.0
----------------------------------------------------------------------------------------------------------------------------------
    GFU 242                                                                                    33.9                           25.0
----------------------------------------------------------------------------------------------------------------------------------
    GFU 243                                                                                    41.7                            0.0
----------------------------------------------------------------------------------------------------------------------------------
    SGRU 1242                                                                                 142.0                           50.0
----------------------------------------------------------------------------------------------------------------------------------
    Offsites--PH 41                                                                            30.0
----------------------------------------------------------------------------------------------------------------------------------
       Sub Total                   0.0        0.0         0.0         0.0          0.0        351.3                          495.0
----------------------------------------------------------------------------------------------------------------------------------
    Percent Usage Ancillary        0.0%       0.0%        0.0%        0.0%         0.0%    (10037.1%)  #DIV/0!  #DIV/0!        8.5%
----------------------------------------------------------------------------------------------------------------------------------
Clark R&M UNITS
----------------------------------------------------------------------------------------------------------------------------------
    GFU 241                                                                                     9.2                           25.0
----------------------------------------------------------------------------------------------------------------------------------
    GFU 244                                                         (10.0)                     59.4                           25.0
----------------------------------------------------------------------------------------------------------------------------------
    HFAU 443                                                                                  114.1                           62.0
----------------------------------------------------------------------------------------------------------------------------------
    SRU 543/544                                                                 (140.0)       (52.0)                         100.0
----------------------------------------------------------------------------------------------------------------------------------
    FCCU 1241                                                      (228.0)      (228.0)       237.4                           90.0
----------------------------------------------------------------------------------------------------------------------------------
    CRU 1344                                            (58.0)                  (186.0)         0.0                          100.0
----------------------------------------------------------------------------------------------------------------------------------
    SWS 8746                                                                                   52.0                          233.0
----------------------------------------------------------------------------------------------------------------------------------
    Cleaning Slab                                                                                                             27.0
----------------------------------------------------------------------------------------------------------------------------------
    P.S 194                                                                                                                   60.0
----------------------------------------------------------------------------------------------------------------------------------
    Cooling Tower Blowdown                                                                                                   800.0
----------------------------------------------------------------------------------------------------------------------------------
    Offsites-PH 136                                                                            99.4
----------------------------------------------------------------------------------------------------------------------------------
    No. 2 WTP                                                                                                                 20.0
----------------------------------------------------------------------------------------------------------------------------------
    Firewater Make-up           (250.0)                                                                  250.0
----------------------------------------------------------------------------------------------------------------------------------
    Fire Water to Sewer                                                                                                      400.0
     for Cooling
----------------------------------------------------------------------------------------------------------------------------------
    Scaltech                                                                                                                  50.0
----------------------------------------------------------------------------------------------------------------------------------
    Storm Water Tank,                                                                                                      2,500.0
     T-1912
----------------------------------------------------------------------------------------------------------------------------------
    Clark R&M Boilers                                  (171.0)                (1,687.0)    (1,389.0)
----------------------------------------------------------------------------------------------------------------------------------
    Filtered Water to Ref.               (2,001.0)
     Dist.
----------------------------------------------------------------------------------------------------------------------------------
    To Filtered Water         (3,936.0)   3,936.0
----------------------------------------------------------------------------------------------------------------------------------
    To Demin./Zeolite                      (725.0)      422.0       303.0
     System
----------------------------------------------------------------------------------------------------------------------------------
    To SMR                                 (718.0)      718.0
    Reject                      (389.0)     (42.0)
----------------------------------------------------------------------------------------------------------------------------------
       Sub Total              (6,480.0)     450.0       911.0        65.0     (2,241.0)      (869.5)                       4,492.0
----------------------------------------------------------------------------------------------------------------------------------
    Percent Usage Clark R&M       79.3%     100.0%      126.9%      100.0%        65.8%     24842.9%   #DIV/0!  #DIV/0!       76.8%
----------------------------------------------------------------------------------------------------------------------------------
       Clark Subtotal                       450.0       911.0        65.0     (2,241.0)      (518.2)                       4,987.0
----------------------------------------------------------------------------------------------------------------------------------
Coker Company & Clark R&M     (7,022.0)     450.0       718.0        65.0     (2,671.0)      (401.8)                       5,422.0
 Sub
----------------------------------------------------------------------------------------------------------------------------------
CHEVRON CCC/PADC                (900.0)       0.0         0.0       (65.0)         0.0        340.0                          425.0
----------------------------------------------------------------------------------------------------------------------------------
    Percent Usage Chevron         11.0%       0.0%        0.0%     (100.0%)        0.0%     (9714.3%)  #DIV/0!  #DIV/0!        7.3%
----------------------------------------------------------------------------------------------------------------------------------
       Refinery Plus CCC      (7,922.0)     450.0       718.0         0.0     (2,671.0)       (61.8)                       5,847.0
        Sub Total
----------------------------------------------------------------------------------------------------------------------------------
DESTEC                                     (450.0)        0.0         0.0          0.0          0.0                            0.0
----------------------------------------------------------------------------------------------------------------------------------
    Percent Usage Destec           0.0%    (100.0%)       0.0%        0.0%         0.0%         0.0%   #DIV/0!  #DIV/0!        0.0%
----------------------------------------------------------------------------------------------------------------------------------
       Ref. Plus CCC Plus     (7,922.0)     450.0       718.0         0.0     (2,671.0)       (61.8)                       5,847.0
        Destec
----------------------------------------------------------------------------------------------------------------------------------
AIR PRODUCTS                    (245.0)       0.0      (718.0)        0.0       (735.0)        58.3
----------------------------------------------------------------------------------------------------------------------------------
    Percent Usage Air Products     3.0%
----------------------------------------------------------------------------------------------------------------------------------
       Net                    (8,167.0)     450.0       718.0        65.0     (3,406.0)        (3.5)       0.0      0.0    5,847.0
----------------------------------------------------------------------------------------------------------------------------------
    Total Percent Usage          100.0%     100.0%      100.0%      100.0%       100.0%       100.0%   #DIV/0!  #DIV/0!      100.0%
</TABLE>

                                      -6-
<PAGE>

                                                                  Schedule 5.5.5
                                                   Services and Supply Agreement

                            COMPRESSED AIR SERVICES

1.   Scope.
     -----

     a.   Supply of the full compressed air requirements of the Coker Company
          for use at the Coker Complex. Such compressed air shall meet the
          specifications set forth in the Turnkey Specifications.

     b.   Supply of the full compressed air requirements of the Coker Company
          for use at the Ancillary Equipment.

2.   Metering/Measurement Methodology for Services to the Coker Complex.

     The meters to be installed pursuant to the EPC Contract and described on
     Schedule 5.5(b) shall be used to measure the thousands of standard cubic
     feet ("MSCF") of compressed air are delivered to the Coker Complex each
     month (the "Monthly Coker Complex MCSF").

3.   Applicable Price.
     ----------------

     a.   Coker Complex

          The Coker Company shall pay Clark R&M for the actual cost of providing
          compressed air to the Coker Complex each month based on the following
          formula:

               Total Average Refinery Compressed Air Cost * Monthly Coker
               Complex MSCF

           Where:

               "Total Average Refinery Compressed Air Cost" means, for any month
               (a) the actual costs in dollars incurred by Clark R&M for the
               production and distribution of compressed air at the Refinery in
               such month, divided by (b) the total amount, expressed in MSCF,
                           ----------
               of compressed air distributed throughout the Refinery in such
               month.

     b.   Ancillary Equipment

          Consideration for compressed air provided by Clark R&M to the Coker
          Company for use at the Ancillary Equipment is included in the
          Ancillary Equipment Operating Fee.

<PAGE>

                                                                  Schedule 5.5.5
                                                   Services and Supply Agreement

4.   Required Billing Information.
     ----------------------------

     Clark R&M shall provide the following information as an attachment to its
     monthly Reconciliation Statements:

     4.1  Total MSCF of compressed air measured through each Coker Complex
          meter.

     4.2  Calculation of the Total Average Refinery Compressed Air Costs

     4.3  Total amount due from Coker Company for compressed air provided to the
          Coker Complex

                                      -2-
<PAGE>

                                                                  Schedule 5.5.6
                                                   Services and Supply Agreement

                               NITROGEN SERVICES

1.   Scope.
     -----

     a.   Supply of the full nitrogen requirements of the Coker Company for use
          at the Coker Complex meeting the following specifications:

               Component                  Specification
               ---------                  --------------

               Nitrogen and inerts        99.999 Mole % minimum
               Oxygen                     10.0 ppm maximum
                                          8.0 ppm minimum
               Moisture (dew point)       - 80[degrees] Fahrenheit or below

     b.   Supply of the full nitrogen requirements of the Coker Company for use
          at the Ancillary Equipment.

2.   Metering/Measurement Methodology for Services to the Coker Complex.

     The meters to be installed pursuant to the EPC Contract and described on
     Schedule 5.5(b) shall be used to measure the volume of nitrogen, expressed
     in thousands of standard cubic feet ("MSCF"), that are delivered to the
     Coker Complex each month (the "Monthly Coker Complex MCSF").

3.   Applicable Price.
     ----------------

     a.   Coker Complex

          The Coker Company shall pay Clark R&M for the actual cost of providing
          nitrogen to the Coker Complex each month based on the following
          formula:

               (Total Average Refinery Nitrogen Cost * Monthly Coker Complex
               MSCF) + Coker Complex Nitrogen Distribution Allocation

          Where:

               "Total Average Refinery Nitrogen Cost" means, for any month, (a)
               the total dollar charges in such month to Clark R&M for nitrogen
               supplied to the Refinery by third party suppliers, divided by (b)
                                                                  ----------
               the Monthly Refinery MSCF.

               "Monthly Refinery MSCF" means, for any month, the total volume of
               nitrogen, expressed in MSCF, purchased by Clark R&M from third
               party suppliers and distributed through the Nitrogen Distribution
               System (as defined in 5 below) in such month.
<PAGE>

                                                                  Schedule 5.5.5
                                                   Services and Supply Agreement

               "Coker Company Nitrogen Distribution Allocation" means, for
               any month (a) the total costs in dollars incurred by Clark R&M in
               such month to maintain the Nitrogen Distribution System (as
               defined below), multiplied by (b) the ratio of (i) Monthly Coker
                               -------------
               Complex MSCF to (ii) Monthly Refinery MSCF.

     b.   Ancillary Equipment

          Consideration for nitrogen provided by Clark R&M to the Coker Company
          for use at the Ancillary Equipment is included in the Ancillary
          Equipment Operating Fee.

4.   Required Billing Information.
     ----------------------------

     Clark R&M shall provide the following information as an attachment to its
     monthly Reconciliation Statements:

     4.1  Total MSCF of nitrogen measured through each Coker Complex meter.

     4.2  Calculation of Total Average Refinery Nitrogen Cost and Coker Complex
          Nitrogen Distribution Allocation.

     4.3  Total amount due from Coker Company for nitrogen provided to the Coker
          Complex

5.   Additional Terms.
     ----------------

     As used herein "Nitrogen Distribution System" means the interconnective
     piping system owned by Clark R&M and used to distribute nitrogen to Clark
     R&M and its affiliates (including the Coker Company).

                                      -2-
<PAGE>

                                                                 Schedule 5.5(b)
                                                   Services and Supply Agreement

                                 UTILITY METERS

     The Coker Company and Clark R&M agree to promptly complete the following
     tables upon completion of design engineering by the Contractor related to
     the applicable meters.

ATU-7841

<TABLE>
<CAPTION>
----------------------------------------------------------------------------------------------------------
 Schedule                 Utility Description               Movement            Flow Meter      Drawing
----------------------------------------------------------------------------------------------------------

              Diagram #         STREAM                  Source/Destination       number         Number
              ---------         ------                  ------------------       -----          ------
                                                                                              7841/4623/
<S>          <C>                <C>                     <C>                      <C>          <C>
----------------------------------------------------------------------------------------------------------
5.5.5         AIR
----------------------------------------------------------------------------------------------------------
                    6           Plant Air                   frm Offsites                         A401
            ----------------------------------------------------------------------------------------------
                    6         Instrument Air                frm Offisites                        A401
            ----------------------------------------------------------------------------------------------

----------------------------------------------------------------------------------------------------------
5.5.6         NITROGEN
----------------------------------------------------------------------------------------------------------
                    1           Nitrogen                    frm Offsites                         A401
            ----------------------------------------------------------------------------------------------

----------------------------------------------------------------------------------------------------------
5.5.2         STEAM
----------------------------------------------------------------------------------------------------------
                    2         MP (125 psig) Steam           frm SWS-8747                         A400
            ----------------------------------------------------------------------------------------------
                    2            50 psig Steam              frm SWS-8747                         A400
            ----------------------------------------------------------------------------------------------

----------------------------------------------------------------------------------------------------------
5.5.4         WATER
----------------------------------------------------------------------------------------------------------
                    3         50 psig Condensate             to SWS-8747                         A400
            ----------------------------------------------------------------------------------------------
                    3          Pumped Condensate             frm SWS-8747                        A400
            ----------------------------------------------------------------------------------------------
                    7           Filtered Water               frm Offisites                       A401
            ----------------------------------------------------------------------------------------------
                    7          Clarified Water               frm Offisites                       A401
            ----------------------------------------------------------------------------------------------
                    5         Cooling Water Supply           frm Offsites                        A401
            ----------------------------------------------------------------------------------------------
                    5         Cooling Water Return            to Offsites                        A401
            ----------------------------------------------------------------------------------------------
                    7            Potable Water               frm Offisites                       A401
----------------------------------------------------------------------------------------------------------
5.5.1         ELECTRIC
----------------------------------------------------------------------------------------------------------
                  N/A         Electric from Clark          from PP6 to ATU-7841    3             N/A
            ----------------------------------------------------------------------------------------------

            ----------------------------------------------------------------------------------------------
</TABLE>

             Note 1: Cooling Tower services all Coker Complex

             Note 2: Natural Gas and Fuel Gas Meter are Reference in the Product
             Purchase Agreements for Coker Complex
<PAGE>

                                                                 Schedule 5.5(b)
                                                   Services and Supply Agreement

SRU-545

<TABLE>
<CAPTION>
--------------------------------------------------------------------------------------------------------------------------------
Schedule            Utility Description                                 Movement            Flow Meter             Drawing
--------------------------------------------------------------------------------------------------------------------------------
               Diagram #            STREAM                           Source/Destination      number                Number
               ---------            ------                           ------------------      ------                ------
<S>            <C>                  <C>                              <C>                    <C>                    <C>
--------------------------
5.5.5          AIR
--------------------------------------------------------------------------------------------------------------------------------
                   6                  Plant Air
               -----------------------------------------------------------------------------------------------------------------

--------------------------------------------------------------------------------------------------------------------------------
5.5.6          NITROGEN
--------------------------------------------------------------------------------------------------------------------------------
                   1                  Nitrogen
               -----------------------------------------------------------------------------------------------------------------

--------------------------------------------------------------------------------------------------------------------------------
5.5.2          STEAM
--------------------------------------------------------------------------------------------------------------------------------
                   2                650 psig Superheated Steam                               FI-1846                 0041
               -----------------------------------------------------------------------------------------------------------------
                   2                 50 psig steam from SCOT WHB                             FI-1681                 0034
               -----------------------------------------------------------------------------------------------------------------
                   2                 50 psig Steam from Cond - Tr1                           FI-1161                 0021
               -----------------------------------------------------------------------------------------------------------------
                   2                 50 psig Steam from Cond - Tr2
               -----------------------------------------------------------------------------------------------------------------

--------------------------------------------------------------------------------------------------------------------------------
5.5.4          WATER
--------------------------------------------------------------------------------------------------------------------------------
                   3                  LP BFW to Condenser - Tr1                              FI-1160                 0021
               -----------------------------------------------------------------------------------------------------------------
                   3                  LP BFW to Condenser - Tr2
               -----------------------------------------------------------------------------------------------------------------
                   3                     LP BFW to SCOT WFB                                  FI-1680                 0034
               -----------------------------------------------------------------------------------------------------------------
                   3                  HP BFW to 650# WHB - Tr1                               FI-1090                 0018
               -----------------------------------------------------------------------------------------------------------------
                   3                  HP BFW to 650# WHB - Tr2
               -----------------------------------------------------------------------------------------------------------------
                   3                  HP BFW to Incinerator Boiler                           FI-1840                 0042
               -----------------------------------------------------------------------------------------------------------------
                   3                   HP BFW to Desuperheater                               FI-1845                 0041
               -----------------------------------------------------------------------------------------------------------------
                                         Quench Water Makeup                                                         0036
               -----------------------------------------------------------------------------------------------------------------
                                          Amine Makep Water                                                          0032
               -----------------------------------------------------------------------------------------------------------------
                                        SCOT ATU SOUR Water                                  FI-1771                 0039
               -----------------------------------------------------------------------------------------------------------------
                   7                       Clarified Water
               -----------------------------------------------------------------------------------------------------------------
                   7                       Filtered Water
               -----------------------------------------------------------------------------------------------------------------
                   5                   Cooling Water Supply
               -----------------------------------------------------------------------------------------------------------------
                   5                   Cooling Water Return
               -----------------------------------------------------------------------------------------------------------------
                   7                       Potable Water
--------------------------------------------------------------------------------------------------------------------------------
5.5.1          ELECTRIC
--------------------------------------------------------------------------------------------------------------------------------
                 N/A                     Electric from Clark          from PP6 to SRU-545        3                    N/A
                                                                                                                  --------------

</TABLE>

                 Note 1: Cooling Tower services all Coker Complex

                 Note 2: Natural Gas and Fuel Gas Meter are Reference in the
                         Product Purchase Agreements for Coker Complex

                                      -2-
<PAGE>

                                                                 Schedule 5.5(b)
                                                   Services and Supply Agreement

HCU-942

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------------------------------
Schedule                   Utility Description                           Movement           Flow Meter            Drawing
---------------------------------------------------------------------------------------------------------------------------------

                    Diagram #                STREAM                 Source/Destination        number              Number
                    ---------                -------                ------------------        ------              ------
                                                                                                                  4612-2--50-
<S>                 <C>                      <C>                    <C>                       <C>                 <C>
-----------------------------
5.5.5               AIR
---------------------------------------------------------------------------------------------------------------------------------
                        6                       Plant Air              frm Offsites                                  062
                    -------------------------------------------------------------------------------------------------------------
                        6                      Instrument Air          frm DCU-843                                   063
                    -------------------------------------------------------------------------------------------------------------

---------------------------------------------------------------------------------------------------------------------------------
5.5.6               NITROGEN
---------------------------------------------------------------------------------------------------------------------------------
                        1                        Nitrogen              frm DCU-843              FI-3026              063
---------------------------------------------------------------------------------------------------------------------------------
5.5.2               STEAM
---------------------------------------------------------------------------------------------------------------------------------
                        2                      HP (650 psig) Steam     frm Offsites             FI-3300              074
                    -------------------------------------------------------------------------------------------------------------
                        2                      MP (125 psig) Steam     frm Offsites             FI-3325              075
                    -------------------------------------------------------------------------------------------------------------

---------------------------------------------------------------------------------------------------------------------------------
5.5.4               WATER
---------------------------------------------------------------------------------------------------------------------------------
                        3                         Condensate            to Offsites                                  076
                    -------------------------------------------------------------------------------------------------------------
                        3                  Surf. Cond. Condensate       to Offsites             FI-3670              088
                    -------------------------------------------------------------------------------------------------------------
                        5                  Cooling Water Sup/Ret        frm Offsites                                 065
                    -------------------------------------------------------------------------------------------------------------
                        7                      Clarified Water          frm DCU-843                                  067
                    -------------------------------------------------------------------------------------------------------------
                        7                        Filter Water           frm DCU-843                                  067
                    -------------------------------------------------------------------------------------------------------------
                        3                   HP Boiler Feed Water        frm Offsites            FI-3276              073
                    -------------------------------------------------------------------------------------------------------------
                        7                       Potable Water           frm Offsites                                 067
                    -------------------------------------------------------------------------------------------------------------
                                                  Sour Water            frm DCU-843                                  054
                    -------------------------------------------------------------------------------------------------------------
                                                  Sour Water            frm SRU-545                                  054
                    -------------------------------------------------------------------------------------------------------------
                                                  Sour Water             to Tank 78             FC-2801              054
---------------------------------------------------------------------------------------------------------------------------------
5.5.1               ELECTRIC
---------------------------------------------------------------------------------------------------------------------------------
                                N/A          Electric from Clark       from PP6 to HCU-942          3                N/A
                    -------------------------------------------------------------------------------------------------------------
                                N/A          Electric from Clark      from PP6 to Cooling Twr       4                N/A
                    -------------------------------------------------------------------------------------------------------------

                    --------------------------------------------                                ---------------------------------
</TABLE>

                    Note 1: Cooling Tower services all Coker Complex

                    Note 2: Natural Gas and Fuel Gas Meter are Reference in the
                            Product Purchase Agreements for Coker Complex

                                      -3-
<PAGE>

                                                                 Schedule 5.5(b)
                                                   Services and Supply Agreement

DCU-843

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------------
     Schedule                Utility Description                 Movement                        Flow Meter              Drawing
-----------------------------------------------------------------------------------------------------------------------------------

                    Diagram #               STREAM           Source/Destination                    number                Number
                    ---------               ------           ------------------                    ------                ------
<S>                 <C>           <C>                        <C>                                 <C>                   <C>
                                                                                                                       4611-2-50-
-------------------------------
      5.5.5        AIR
-----------------------------------------------------------------------------------------------------------------------------------
                       6                  Plant Air                 to DCU-843                   FE-3615                  171
                 ------------------------------------------------------------------------------------------------------------------
                       6               Instrument Air               to DCU-843                                            171
                 ------------------------------------------------------------------------------------------------------------------
                       6                  Plant Air                 to HCU-942                                            172
                 ------------------------------------------------------------------------------------------------------------------
                       6               Instrument Air               to HCU-942                                            172
                 ------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------------
      5.5.6        NITROGEN
-----------------------------------------------------------------------------------------------------------------------------------
                       1                  Nitrogen                  to DCU-843                   FE-3616                  171
                 ------------------------------------------------------------------------------------------------------------------
                       1                  Nitrogen                  to HCU-942                                            172
                 ------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------------
      5.5.2        STEAM
-----------------------------------------------------------------------------------------------------------------------------------
                       2            MP (125 psig) Steam           to/from DCU-843                FE-3623                  171
                 ------------------------------------------------------------------------------------------------------------------
                       2            HP (650 psig) Steam             to DCU-843                   FE-3624                  171
                 ------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------------
      5.5.4        WATER
-----------------------------------------------------------------------------------------------------------------------------------
                       5            Cooling Water Supply            to DCU-843                   FE-3621                  171
                 ------------------------------------------------------------------------------------------------------------------
                       5            Cooling Water Return           frm DCU-843                                            171
                 ------------------------------------------------------------------------------------------------------------------
                       3             High Pressure BFW              to DCU-843                   FE-3637                  172
                 ------------------------------------------------------------------------------------------------------------------
                       3            Medium Pressure BFW             to DCU-843                   FE-3638                  172
                 ------------------------------------------------------------------------------------------------------------------
                       3          High Pressure Condensate          to Deaerator                 FE-3639                  172
                 ------------------------------------------------------------------------------------------------------------------
                       3          Low Pressure Condensate           to Deaerator                 FE-3640                  172
                 ------------------------------------------------------------------------------------------------------------------
                       7                 Oily Water                 to WWTU                        F?                     171
                 ------------------------------------------------------------------------------------------------------------------
                       9             Phenolic Sour Water            to HCU-942                 FE1853,1992                172
                 ------------------------------------------------------------------------------------------------------------------
                       7                Potable Water               to DCU-843                                            171
                 ------------------------------------------------------------------------------------------------------------------
                       7               Clarified Water              to DCU-843                   FE-3620                  171
                 ------------------------------------------------------------------------------------------------------------------
                       7                Filtered Water              to DCU-843                   FE-3620                  171
                 ------------------------------------------------------------------------------------------------------------------
                       7                Clarified Water             to HCU-942                                            172
                 ------------------------------------------------------------------------------------------------------------------
                       7                Filtred Water               to HCU-942                                            172
-----------------------------------------------------------------------------------------------------------------------------------
      5.5.1        ELECTRIC
-----------------------------------------------------------------------------------------------------------------------------------
                       N/A              Electric from Clark       from PP6 to DCU-843               2                     N/A
                 ------------------------------------------------------------------------------------------------------------------
                       N/A              Electric from Clark     from PP6 to Feed Tanks              4                     N/A
                 ------------------------------------------------------------------------------------------------------------------

                 ------------------------------------------------------------------------------------------------------------------
</TABLE>

                 Note 1: Cooling Tower services all Coker Complex

                 Note 2: Natural Gas and Fuel Gas Meter are Reference in the
                         Product Pruchase Agreements for Coker Complex
                         SWS-8747

                                     -4-
<PAGE>

                                                                 Schedule 5.5(b)
                                                   Services and Supply Agreement

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------------
     Schedule                Utility Description                 Movement                        Flow Meter              Drawing
-----------------------------------------------------------------------------------------------------------------------------------

                     Diagram #               STREAM           Source/Destination                    number              Number
                     ---------               ------           ------------------                    ------              ------
<S>                  <C>            <C>                       <C>                                <C>                    <C>
                                                                                                                        8747/4622/

-----------------------------------------------------------------------------------------------------------------------------------
      5.5.5        AIR
-----------------------------------------------------------------------------------------------------------------------------------
                       6                  Plant Air               frm Offsites                                             A401
                 ------------------------------------------------------------------------------------------------------------------
                       6                Instrument Air            frm Offisites                                            A401
-----------------------------------------------------------------------------------------------------------------------------------
      5.5.6        NITROGEN
-----------------------------------------------------------------------------------------------------------------------------------
                       1                  Nitrogen                frm Offsites                                             A401
-----------------------------------------------------------------------------------------------------------------------------------
      5.5.2        STEAM
-----------------------------------------------------------------------------------------------------------------------------------
                       2              MP (125 psig) Steam        to SWS 8747                     FI-1033                   A400
                 ------------------------------------------------------------------------------------------------------------------
                       2                50 psig Steam            to SWS 8747                     FI-1032                   A400
-----------------------------------------------------------------------------------------------------------------------------------
      5.5.4        WATER
-----------------------------------------------------------------------------------------------------------------------------------
                       3             50 psig Condensate          frm SWS 8747                                              A400
                 ------------------------------------------------------------------------------------------------------------------
                       3            Pumped Condensate             to SWS 8747                                              A400
                 ------------------------------------------------------------------------------------------------------------------
                       7                Clarified Water           frm Offisites                                            A401
                 ------------------------------------------------------------------------------------------------------------------
                       5            Cooling Water Supply          frm Offsites                                             A401
                 ------------------------------------------------------------------------------------------------------------------
                       5            Cooling Water Return          to Offsites                                              A401
                 ------------------------------------------------------------------------------------------------------------------
                       7                Potable Water             frm Offisites                                            A401
-----------------------------------------------------------------------------------------------------------------------------------
      5.5.1        ELECTRIC
-----------------------------------------------------------------------------------------------------------------------------------
                       N/A            Electric from Clark     from PP6 to SWS-8747                  3                       N/A
                 ------------------------------------------------------------------------------------------------------------------

                 ------------------------------------------------------------------------------------------------------------------
</TABLE>

                 Note 1: Cooling Tower services all Coker Complex
                 Note 2: Natural Gas and Fuel Gas Meter are Reference in the
                         Product Pruchase Agreements for Coker Complex

                                      -5-

<PAGE>

                                                                    Schedule 5.6
                                                   Services and Supply Agreement

     WASTE MANAGEMENT AND WASTEWATER TREATMENT SERVICES

5.   1.  Scope.
         -----

     Collection, processing, treatment, transportation, storage, disposal and
     recycling of all waste generated by the Heavy Oil Processing Facility and
     all rain water runoff, cooling tower blow down, sanitary sewage (but the
     cost of sanitary sewage service is included in the rent payable under the
     Coker Complex Ground Lease and the Ancillary Equipment Site Lease,
     respectively), recovered oil, recovered residuals and all other hazardous
     and solid waste originating at the Heavy Oil Processing Facility ("Waste
     Management and Wastewater Treatment Services").

     1.1  Wastewater Treatment Services

          Clark R&M shall provide wastewater treatment services to the Coker
          Company through operation of the following four systems of Clark R&M's
          waste water treatment facility at the Refinery (the "WWTF").

          f.   Waste Treatment System ("WTS")

               A contaminant based unit that is the main treatment facility at
               the Refinery. It handles treatment of all flow from the Dirty
               Water Collection System (defined below) and the dry weather
               Surface Drainage System (defined below) and all cooling tower
               blowdown at the Refinery.

          g.   Dirty Water Collection System ("DWCS")

               All equipment at the Refinery used for collection and convergence
               of dirty water to the WTS, including all pumping, tanks, piping,
               and reservoirs.

          h.   Surface Drainage System ("SDS")

               This system handles all surface drainage at the Refinery and
               currently consist of Clark R&M's pump house no. 15 and tanks nos.
               1912 and 1913.

          d.   Oil Recovery Unit ("ORU")

               This system handles recovered oil, recovered residuals and
               hazardous and solid wastes (including, without limitation, slop
               oil emulsions) from the WTS and vacuum trucks.

     1.2. Waste Management System ("WMS")

          Clark R&M shall utilize its WMS to provide waste management services
          for the Heavy Oil Processing Facility including, without limitation,
          all labor, equipment, vehicles, administration, contract manpower and
          other resources necessary for
<PAGE>

                                                                    Schedule 5.6
                                                   Services and Supply Agreement

          spill response, spill site remediation and the collection, storage,
          treatment, transportation and disposal of non-hazardous and hazardous
          waste.

6.   Metering/Measurement Methodology for Services to the Coker Complex.
     ------------------------------------------------------------------

     2.1  WTS

          a.   The monthly usage of the WTS by the Coker Complex ("Monthly WTS
               Allocation") shall be deemed to equal sixteen percent (16%) of
               the total monthly usage of the WTS.

          b.   Pursuant to Section 7.4(b) of this Services and Supply Agreement,
               from time to time, the parties may modify the Monthly WTS
               Allocation based on their best efforts to determine the actual
               dirty water volume attributable to the Coker Complex.

     2.2  DWCS

          The monthly usage of the DWCS by the Coker Complex (the "Monthly DWCS
          Allocation") shall be deemed to equal twenty five percent (25%) of the
          total monthly usage of the DWCS.

     2.3  SDS

          The monthly usage of the SDS by the Coker Complex (the "Monthly SDS
          Allocation") shall equal (i) 47.7 (which is the total number of acres
          occupied by the Coker Complex), divided by (ii) 2300 (which is the
                                          ----------
          total number of acres drained by Clark R&M's pump house no. 15 located
          at the Refinery).

     2.4  ORU

          a.   The monthly usage of the ORU  by the Coker Complex (the "Monthly
               ORU Allocation") shall be deemed to equal twenty five percent
               (25%) of the total monthly usage of the ORU.

          b.   Pursuant to Section 7.4(b) of this Services and Supply Agreement,
               from time to time, the parties shall use their best efforts to
               modify the Monthly ORU Allocation based on the actual volume of
               slop oil emulsions, solids, recovered oil, recovered residuals,
               vacuum truck deliveries and other wastes handled by the ORU and
               attributable to the Coker Complex.

     2.5  Waste Management System

          a.   The monthly usage of the WMS by the Coker Complex (the "Monthly
               WMS Allocation") shall be deemed to equal 15% of the total usage
               of the WMS.

                                      -2-
<PAGE>

                                                                    Schedule 5.6
                                                   Services and Supply Agreement

          b.   Pursuant to Section 7.4(b) of this Services and Supply
               Agreement, from time to time, the parties may modify the Monthly
               WMS Allocation based on their best efforts to determine actual
               waste volume attributable to the Coker Complex.

3.   Applicable Price.
     ----------------

     3.1  Coker Complex

          c.   WTS

               The Coker Company shall pay Clark R&M for providing Waste
               Management and Wastewater Treatment Services at the WTS each
               month according to the following formula:

                    Total WTS Cost * Monthly WTS Allocation

               Where:

                    "Total WTS Cost" means, for any month, the sum of (i) all
               Permitted Reimbursable Expenses incurred by Clark R&M in
               operating its waste water treatment unit designated WWTU 8743 at
               the Refinery and (ii) without duplication, all Permitted
               Reimbursable Expenses incurred by Clark R&M associated with the
               treatment of dirty water at the Refinery and the processing of
               oil, recovered oil, recovered residuals, emulsions, oily solids
               and oily sludge generated at the WTS.

          d.   DWCS

               The Coker Company shall pay Clark R&M for providing Waste
               Management and Wastewater Treatment Services at the DWCS each
               month according to the following formula:

                    Total DWCS Cost * Monthly DWCS Allocation

               Where:

                    "Total DWCS Cost" means, for any month, all Permitted
                    Reimbursable Expenses incurred by Clark R&M in operating the
                    DWCS.

          e.   SDS

               The Coker Company shall pay Clark R&M for providing Waste
               Management and Wastewater Treatment Services at the SDS each
               month according to the following formula:

                                      -3-
<PAGE>

                                                                    Schedule 5.6
                                                   Services and Supply Agreement

                    Total SDS Cost * Monthly SDS Allocation

               Where:

                    "Total SDS Cost" means, for any month, the Permitted
                    Reimbursable Expenses incurred by Clark R&M in operating the
                    SDS.

          f.   ORU

               The Coker Company shall pay Clark R&M for providing Waste
               Management and Wastewater Treatment Services at the ORU each
               month according to the following formula:

                    Total ORU Cost * Monthly ORU Allocation

          Where:

                    "Total ORU Cost" means, for any month, the Permitted
                    Reimbursable Expenses incurred by Clark R&M in operating the
                    ORU.

          WMS

               The Coker Company shall pay Clark R&M for providing Waste
               Management and Waste Water Treatment Services described above
               under 1.2 each month according to the following formula:

                    Total WMS Cost * Monthly WMS Allocation

               Where:

                    "Total WMS Cost" means, for any month, the Permitted
                    Reimbursable Expenses incurred by Clark R&M in operating its
                    WMS.

     3.2  Ancillary Equipment

          Consideration for Waste Management and Wastewater Services provided by
          Clark R&M to the Coker Company for use at the Ancillary Equipment is
          included in the Ancillary Equipment Operating Fee.

7.

                                      -4-
<PAGE>

                                                                  Schedule 5.7.1
                                                   Services and Supply Agreement

                       SULFUR AND COKE TRANSPORT SERVICES

1.   Scope.
     -----

     1.1       Truck Weighing

               Clark R&M shall maintain and operate truck scales at the Refinery
               for the purposes of weighing sulfur trucks on behalf of the Coker
               Company.

     1.2       Rail Services

               Clark R&M shall provide all railroad services necessary to
               transport petroleum coke and sulfur from the Heavy Oil Processing
               Facility, including, without limitation, (i) receiving inbound
               railcars from serving railroad carriers, sorting and weighing
               such cars and delivering them to the Coker Complex or Ancillary
               Equipment, as the case may be; (ii) receiving outbound rail cars
               from the Coker Complex and the Ancillary Equipment, sorting and
               weighing such cars and delivering them to serving railroad
               carriers; and (iii) providing switching to facilitate loading,
               unloading and maintenance activities for such railcars.

     1.3       Coker Handling

               Clark R&M shall provide all coke handling services necessary to
               transport petroleum coke to the delivery point for such Product
               under the Product Purchase Agreement.

2.   Applicable Price.
     ----------------

     The cost to Clark R&M of providing sulfur and coke transport Services to
     the Coker Company is reflected in the purchase price of such Products under
     the Product Purchase Agreement.
<PAGE>

                                                                 Schedule 5.7.2
                                                   Services and Supply Agreement

                   BROAD BAND AND NETWORK COMPUTING SERVICES

1.   Scope.
     -----

     1.1       Clark R&M shall install all necessary coaxial cable connections
               and television sets for Coker Company control rooms in order to
               connect the Coker Company and its employees to the broad band
               closed circuit televisions network at the Refinery which provides
               video information throughout the Refinery, including, without
               limitation, a bulletin board system, doppler radar, safety
               information and information on operations meetings.

     1.2       Clark R&M shall provide network computing services to the Coker
               Company, including without limitation:

               a.   Installation of cable connections and desktop computers with
                    appropriate office software at the Coker Company's business
                    office and control room locations

               b.   Connection to Clark R&M's local area network, wide area
                    network, intranet, internet, e-mail system and the Refinery
                    information system.

     1.3       Clark R&M shall provide routine hardware repairs, system problem
               isolation and resolution, help desk service, network
               administration and management, computer backup services and
               testing for the Coker Company's broad band and computer network
               connections and all equipment, hardware and software related
               thereto.

2.   Applicable Price.
     ----------------

     2.1. The Coker Company shall reimburse Clark R&M for Permitted Reimbursable
          Expenses in connection with equipment procurement and installation of
          (a) the broad band cable connections for the Coker Company and (b)
          desktop computer(s) and software and installation of the cable
          connection(s) for the Coker Company.

     2.2       The Coker Company shall pay Clark R&M the following fee each
               month for all services provided by Clark R&M pursuant to 1.3
               above: (a) for any month after the equipment described in 1.1 and
               1.2 above is installed and connected and prior to and including
               December 2000, $2100.00 and (b) for any month thereafter,
               $2100.00, multiplied by the Inflation Factor.
                         -------------
<PAGE>

                                                                  Schedule 5.7.3
                                                   Services and Supply Agreement

                           RADIO AND PHONE SERVICES

1.   Scope.
     -----

     1.1       Trunked Radio Services

               a.   Clark R&M shall  maintain (through a third party service
                    provider) and operate the radio antenna, computers, repeater
                    stations, mobile units and base stations used in connection
                    with the Refinery's 800 megaherz Federal Communications
                    Commission license (collectively, the "Trunked Radio
                    System").

               b.   Clark R&M shall provide the Coker Company with access to the
                    Trunked Radio System.  Such access shall be limited to the
                    business purposes of the Coker Company and its affiliates.

               c.   Clark R&M shall procure all necessary portable 800 megahertz
                    radios on behalf of the Coker Company and provide on-going
                    repair and maintenance (through a third party service
                    provider) for such radios.

               d.   Trunked Radio Services and related portable radio services
                    are currently provided under Clark R&M's service contract
                    with Motorola Communications, Inc.  All radios used by the
                    Coker Company shall be added to the inventory covered by
                    this service agreement.

     1.2       Telephone Services

               Clark R&M shall provide all labor for routine hardware and
               software repairs, system problem isolation and resolution, cable
               installation, telephone installation, PBX administration and
               management, backup services, help desk services and testing for
               the telephone environment at the Coker Complex and the business
               offices of the Coker Company.

2.   Applicable Price.
     ----------------

     2.1       Trunked Radio Services

               a.   The Coker Company shall reimburse Clark R&M for the purchase
                    price of each radio procured on behalf of the Coker Company.

               b.   The Coker Company shall pay Clark R&M the following fee for
                    all other Services described in 1.1 above each month: (a)
                    for any month after the Start-up Date and prior to and
                    including
<PAGE>

                                                                  Schedule 5.7.3
                                                   Services and Supply Agreement

                    December 2000, $670.00 and (b) for any month thereafter,
                    $670.00, multiplied by the Inflation Factor.
                             -------------

               c.   Upgrades to the Trunked Radio System agreed upon mutually by
                    Clark R&M and Coker Company to increase the reliability of
                    the system, the Coker Company will be responsible for a
                    percentage of the cost of any upgrade performed to increase
                    the reliability of the Trunked Radio System, provided that,
                                                                 --------
                    prior to initiating such upgrade Clark R&M and the Coker
                    Company have agreed to (i) the undertaking of such upgrade,
                    (ii) the estimated cost of such upgrade and (iii) a
                    percentage sharing of such cost based on the number of
                    radios used by each party at such time.

     2.2       Telephone Services

               a.   The Coker Company shall reimburse Clark R&M for all
                    Permitted Reimbursable Expenses incurred by Clark R&M in
                    connection with installation of phone lines at the Coker
                    Complex and the procurement of telephones and other
                    equipment in connection therewith on behalf of the Coker
                    Company.

               b.   The Coker Company shall pay Clark R&M the following fee for
                    all other Services described in 1.2 above each month: (a)
                    for any month after the Coker Company telephone environment
                    described in 1.2 above is installed and prior to and
                    including December 2000, $500.00 and (b) for any month
                    thereafter, $500.00, multiplied by the Inflation Factor.
                                         -------------

                                      -2-
<PAGE>

                                                                  Schedule 5.7.4
                                                   Services and Supply Agreement

              ANALYTICAL LABORATORY AND CUSTODY TRANSFER SERVICES

1.   Scope.
     -----

     1.1       Analytical Laboratory Services

               a.   Clark R&M shall provide analytical laboratory services to
                    the Coker Company in a manner substantially similar to the
                    manner that such services have been provided at the Refinery
                    in the past.

               b.   Clark R&M shall provide (i) the analytical tests identified
                    in the Schedules to the Product Purchase Agreement under the
                    heading "Test Method" and (ii) such other tests that are
                    necessary to determine the quantity and quality of Products
                    produced by the Heavy Oil Processing Facility or to which
                    the parties otherwise mutually agree (collectively, "Coker
                    Company Lab Tests").

               c.   Clark R&M shall furnish the Coker Company with the results
                    obtained from all Coker Company Lab Tests within the same
                    time frame as results from similar tests have historically
                    been provided, typically 4 to 8 hours for routine tests and
                    typically 60 minutes for rush tests.  The Coker Company (or
                    a party acting on behalf of the Coker Company) shall have
                    the right to audit the procedures used to perform each Coker
                    Company Lab Tests and to recommend changes thereto and to
                    the number and types of tests performed.

     1.2       Custody Transfer Services

               Clark R&M shall provide all other services related to
               quantification of hydrocarbon receipts or deliveries,
               coordination of third party inspections and maintain appropriate
               procedures for Clark R&M and Coker Company employees to follow to
               ensure accurate Product measurement.

2.   Applicable Price.
     ----------------

     2.1       Coker Complex

               a.   The Coker Company shall pay Clark R&M the following fee
                    analytical lab services provided under 1.1 above for the
                    Coker Complex: (a) for any month after the Start-up Date and
                    prior to and including December 2000, $35,000 and (ii) for
                    any month thereafter, $35,000, multiplied by the Inflation
                                                   -------------
                    Factor.
               b.   The Coker Company shall also reimburse Clark R&M for a
                    proportional share of the costs of any laboratory equipment
                    purchased for performing Coker Complex testing.
<PAGE>

               c.   The Coker Company shall pay Clark R&M the following fee for
                    providing custody transfer services described under 1.2
                    above related to the Coker Complex: (a) for any month after
                    the Start-up Date and prior to and including December 2000,
                    $11,700 and (ii) for any month thereafter, $11,700,
                    multiplied by the Inflation Factor.
                    -------------

     2.2  Ancillary Equipment

          Consideration for analytical lab provided by Clark R&M to the Coker
          Company related to the Ancillary Equipment and the Ancillary Equipment
          Site is provided for in the Ancillary Equipment Operating Fee.

                                      -2-
<PAGE>

                                                                  Schedule 5.7.5
                                                   Services and Supply Agreement

                               SECURITY SERVICES

1.   Scope.
     -----

     1.1.      Clark R&M security personnel will monitor entrance and access to
               the Refinery to ensure the safety and security of all Coker
               Company and Clark R&M employees.

     1.2       Clark R&M security personnel will also ensure compliance with
               Foreign Trade Zone regulations.

2.   Applicable Price.
     ----------------

     The Coker Company shall pay Clark R&M the following fee for security
     services provided each month: (a) for any month prior to and including
     December 2000, $25,000 and (b) for any month thereafter, $25,000,
     multiplied by the Inflation Factor.
     -------------
<PAGE>

                                                                  Schedule 5.7.6
                                                   Services and Supply Agreement

                            OTHER SUPPORT SERVICES

1.   Scope.
     -----

     1.1          Procurement and Contract Services

                  Clark R&M shall manage the day to day procurement of
                  equipment, materials, supplies and services provided to the
                  Coker Company by Clark R&M and use commercially reasonable
                  efforts to ensure that related procurement charges are
                  separately allocated to each unit comprising the Heavy Oil
                  Processing Facility and identifiable from any other charges to
                  Clark R&M.

     1.2          Open Stores

                  Clark R&M shall coordinate and maintain open stores for
                  standard materials or equipment needed for operation of the
                  Heavy Oil Processing Facility (other than Coker Company Spare
                  Parts) either to be made readily available at Clark R&M's on-
                  site Refinery warehouse or at a reasonably accessible vendor
                  site.

     1.3          General Supplies

                  Clark R&M shall maintain adequate supplies for the day to day
                  operation of the Heavy Oil Processing Facility including,
                  without limitation, janitorial supplies, lubricants, office
                  and copier supplies, toiletries, and specialty detergents

     1.4          Warehousing

                  Clark R&M shall maintain segregated storage facilities for
                  Coker Company Spare Parts as required by Section 5.9(a) of the
                  Services and Supply Agreement.  These warehousing facilities
                  shall be on either Refinery property or off-site warehousing
                  facilities depending on specialty storage requirements per the
                  equipment manufacturer specifications.

2.   Applicable Price.
     ----------------

     The Coker Company shall pay Clark R&M the following fee for providing the
     Services described in this Schedule: (a) for any month prior to and
     including December 2000, $24,000 and (b) for any month thereafter, $24,000,
     multiplied by the Inflation Factor.
     -------------
<PAGE>

                                                                  Schedule 5.8.1
                                                   Services and Supply Agreement

                              OPERATIONS SERVICES

1.   Scope.
     -----

     1.1          Operations Oversight

                  A Clark R&M operations manager shall be responsible for the
                  safe, environmentally sound, and profitable operation of the
                  Heavy Oil Processing Facility.  Such individual (or
                  individuals) shall be responsible for (i) monitoring key
                  operational and organizational variables to assure that
                  adequate procedures, processes, and personnel are in place to
                  accomplish and set operational goals for the Heavy Oil
                  Processing Facility, (ii) asset management, including
                  monitoring and assuring the assets under his/her control are
                  operated and maintained in good working order in regards to
                  Prudent Industry Practices, (iii) optimization, including
                  working with other Refinery groups to assure units are
                  optimized to achieve the greatest return on investment and
                  (iv) personnel, including managing personnel associated with
                  the Coker Company in regards to performance and staffing.

     1.2.         Shift Supervision

                  a.   A Clark R&M shift supervisor shall have primary
                       responsibility for the following related to the Heavy Oil
                       Processing Facility:  (i) shift process coordination,
                       (ii) operation and maintenance, (iii) unit coordination
                       of products and feedstocks and (iv) initial response for
                       incidents.  Such position shall be staffed continuously,
                       during off-hours and weekends.

                  b.   Three Clark R&M process operating supervisors shall
                       supervise all unit operators at the Heavy Oil Processing
                       Facility to accomplish unit and Refinery objectives.
                       Such individuals shall  assure that each unit is operated
                       in a safe, environmentally sound, and efficient manner
                       and shall monitor day to day operations, coordinate with
                       planning and scheduling groups, set maintenance
                       priorities, and manage unit operating personnel.

     1.3          Feed and Product Scheduling

                  A Clark R&M feed and product scheduler shall have primary
                  responsibility for product inventory logistics that are
                  required to manage feedstocks, intermediates and finished
                  products for the Heavy Oil Processing Facility.  Such
                  individual (or individuals) shall (a) monitor and /track feed
                  and product inventories, (b) schedule feed and product
                  movements based on input from the Clark R&M's planning and
                  economics group, and (c) serve as the primary contact with
                  product sales personnel in order to monitor current market
                  statistics.

2.   Applicable Price.
     ----------------

     2.1          Coker Complex
<PAGE>

                                                                  Schedule 5.8.1
                                                   Services and Supply Agreement

                  a.  The Coker Company shall pay Clark R&M the following fee
                      for providing the Services described in 1.1 above related
                      to the Coker Complex: (a) for any month after the Start-up
                      Date and to and including December 2000, $11,700 and (b)
                      for any month thereafter, $11,700, multiplied by the
                      Inflation Factor .                 -------------

                  b.  The Coker Company shall pay Clark R&M the following fee
                      for providing the Services described in 1.1 above related
                      to the Coker Complex: (a) for any month after the Start-up
                      Date and prior to and including December 2000, $22,500 and
                      (b) for any month thereafter, $22,500, multiplied by
                                                             -------------
                      the Inflation Factor.

                  c.   The Coker Company shall pay Clark R&M the following fee
                       for providing the Services described in 1.1 above related
                       to the Coker Complex: (a) for any month after the Start-
                       up Date and prior to and including December 2000, $4,200
                       and (b) for any month thereafter, $4,200, multiplied by
                                                                 -------------
                       the Inflation Factor.

            2.2   Ancillary Equipment

                  Consideration for operations services provided by Clark R&M to
                  the Coker Company related to the Ancillary Equipment and the
                  Ancillary Equipment Site is provided for in the Ancillary
                  Equipment Operating Fee.

                                      -2-
<PAGE>

                                                                  Schedule 5.8.2
                                                   Services and Supply Agreement

                             ENGINEERING SERVICES

1.   Scope.
     -----

     Clark R&M engineers shall provide the following services:

     1.1       Technical Support and Capital Planning

               a.   Provide oversight to ensure that engineering and industry
                    standards are followed at the Heavy Oil Processing
                    Facility

               b.   Complete routine technical inspections in accordance with
                    industry practice to help maintain unit reliability, plan
                    future turnarounds and capital upgrades at the Heavy Oil
                    Processing Facility

     1.2       Optimization and Scheduling

               a.   Run unit models with input from Refinery optimization
                    group to set optimal process targets to achieve the
                    highest profitability

               b.   Review current and future feed and product markets,
                    current operating parameters and product specifications,
                    and set operating targets

               c.   Provide data to schedule operating rates and product
                    specification targets

     1.3       Design, Drafting, Reproduction and Record Management

               a.   Provide engineering oversight/supervision necessary to
                    improve unit reliability and throughput.

               b.   Provide engineering design complete with calculations and
                    material/equipment selections consistence with most cost
                    effect technology and material available.

               c.   Provide drafting/graphics services required to capture and
                    convey engineering designs to construction, operation, and
                    maintenance forces. Maintain life cycle process safety
                    information (PSI) and drawings necessary to meet the needs
                    of the business and comply with the requirements of OSHA
                    1910.119.

               d.   Provide reproduction and distribution services for text
                    (8.5 x 11) through large format (E size) engineering
                    drawings and maps.

               e.   Maintain a central engineering file to meet the needs of
                    the business and comply with the requirements of OSHA
                    1910.119.

     1.4       Project Management and Reliability Support
<PAGE>

                                                                 Schedule 5.8.2
                                                  Services and Supply Agreement

                  a.   Provide management of Services to be provided by Clark
                       R&M pursuant to Section 5.3 of the Services and Supply
                       Agreement.

                  b.   Identify and resolve problems

                  c.   Perform mechanical failure investigations.

                  d.   Provide technical input for improving the long-term
                       reliability of the Heavy Oil Processing Facility.

                  e.   Liaison with project management and project safety
                       management to plan for and execute major maintenance and
                       capital planning for the Heavy Oil Processing Facility.

     1.5          Process and Control Engineering

                  a.   Provide supplemental management support to process
                       engineering and optimization for Heavy Oil Processing
                       Facility.

                  b.   Monitor and track unit performance by developing key
                       performance parameters.

                  c.   Work with the operating supervisors and unit operators to
                       improve performance, develop improvement projects, and
                       develop and accomplish long term goals.

                  d.   Provide control engineering including monitoring and
                       developing  process control configurations to optimize
                       and maximize the utilization of the Coker Company's
                       assets.

                  e.   Monitor and track computer control equipment and
                       instrumentation performance including simple loop and
                       advanced control software, and tracking and continually
                       improving system uptimes.

                  f.   Interact with unit operational and maintenance personnel,
                       the optimization group at the Refinery and other
                       engineering personnel.

     1.6          Engineering Studies and Strategic Planning

                  Provide long-term planning for management of the Heavy Oil
                  Processing Facility and analysis of performance of the Heavy
                  Oil Processing Facility.

2.   Applicable Price.
     ----------------

     2.1          Coker Complex

                                      -2-
<PAGE>

                                                                  Schedule 5.8.2
                                                   Services and Supply Agreement

                  a.   The Coker Company shall reimburse Clark R&M for all
                       Permitted Reimbursable Expenses incurred by Clark R&M in
                       utilizing outside professional services and consultants
                       necessary for the performance of engineering support
                       services related to the Coker Complex each month

                  b.   The Coker Company shall pay Clark R&M the following fee
                       for the performance of all other engineering support
                       services related to the Coker Complex: (i) for each month
                       after the Start-up Date and prior to and including
                       December 2000, $50,000 and (ii) for each month
                       thereafter, $50,000, multiplied by the Inflation Factor.
                                            -------------

          2.2     Ancillary Equipment

                  Consideration for engineering services provided by Clark R&M
                  to the Coker Company related to the Ancillary Equipment and
                  the Ancillary Equipment Site is provided for in the Ancillary
                  Equipment Operating Fee.

                                      -3-
<PAGE>

                                                                  Schedule 5.8.3
                                                   Services and Supply Agreement

                                HUMAN RESOURCES

1.   Scope.
     -----

     Clark R&M shall provide the following human resource functions for the
     benefit of Coker Company employees:

     1.1  Labor Management

          Negotiate and administer collective bargaining agreements for
          represented employees of the Coker Company.

     1.2  Payroll Administration

          Oversee the full payroll process for Coker Company delivering
          accuracy and timeliness by ensuring process system
          effectiveness.

     1.3  Employee Training

          Ensure regulatory compliance and requisite skills training for
          Coker Company employees associated with the safe and efficient
          operation of the Coker Complex.

     1.4  Benefits

          Administer benefits for Coker Company employees in accordance
          with applicable benefit plans for both exempt/non-exempt and
          represented wage classifications.

     1.5  Employee Relations

          Handle daily human resources activities as required for
          employees of Coker Company including, without limitation,
          recruitment, litigation, wages, administration of collective
          bargaining agreements, employee activities and other human
          resources functions.

     1.6  Medical Services

          Provide pre-employment physicals, drug and alcohol screens,
          and assessment that employees are "fit for duty" when
          reporting back to work after illness or injury.

2.   Applicable Price.
     ----------------

     The Coker Company shall pay Clark R&M for providing human resource services
     each month according to the following formula:
<PAGE>

                                                                  Schedule 5.8.3
                                                   Services and Supply Agreement

                  Direct Coker Company Cost +  Refinery Human Resources Cost  *
                  Coker Company Employees
                  -----------------------
                  Refinery Employees

               Where:

                  "Direct Coker Company Cost" means, for any month, Permitted
                  Reimbursable Expenses incurred by Clark R&M and directly
                  attributable to human resource functions provided exclusively
                  for the Coker Company or its employees including, without
                  limitation, recruitment agency fees for recruitment of Coker
                  Company employees, litigation relating exclusively to actions
                  of Coker Company employees and relocation expenses for Coker
                  Company employees.

                  "Refinery Human Resources Costs" means, for any month, the
                  difference between (a) the Permitted Reimbursable Cost
                  incurred by Clark R&M in providing the human resource
                  functions described above for Clark R&M and its affiliates
                  (including the Coker Company) at the Refinery, minus (b)
                                                                 -----
                  Direct Coker Company Cost.

                  "Coker Company Employees" means, for any month, the average
                  number of individuals employed by the Coker Company.

                  "Refinery Employees" means, for any month, the sum of (a) the
                  average number of individuals employed by the Coker Company in
                  such month and (b) the average number of individuals employed
                  by Clark R&M and it affiliates (other than the Coker Company)
                  that are designated Refinery employees.

                                      -2-
<PAGE>

                                                                  Schedule 5.8.4
                                                   Services and Supply Agreement

                              ACCOUNTING SERVICES

1.   Scope.
     -----

     Clark R&M shall provide the following accounting services in connection
     with performance of its obligations under the Services and Supply
     Agreement:

     1.1. Billing Information

          a.   Products

               Provide the Coker Company with all information necessary to (i)
               quantify and document feedstocks to and Products from each Heavy
               Oil Processing Facility unit, (ii) attach value to each of these
               feedstocks and Products based on applicable fees in the Services
               and Supply Agreement and the Product Purchase Agreement and (iii)
               monitor all the laboratory data for such feedstocks and Products.

          b.   Services

               Provide the Coker Company with all information necessary
               to monitor and quantify each Service provided to the
               Coker Company by Clark R&M

          c.   Invoices

               Provide the Coker Company with drafts of invoices in
              connection with payments to be made by Clark R&M to the
              Coker Company pursuant to the Product Purchase Agreement.

     1.2  General Accounting Information

          Provide the Coker Company with information necessary to (i)
          ensure that all Federal and State Tax guidelines are
          incorporated into its accounting activities and (ii) prepare
          reconciliation analysis of the its inventory, fixed assets and
          authorization for expenditures for capital or turnaround
          documentation.

     1.3  Financial Reporting, Budget Coordination and Strategic Planning

          Provide the Coker Company with drafts of monthly cost
          analysis, planning and budgeting guidelines and the Annual
          Budget and Operating Plan in a timely manner.

     1.4  Yield Accounting

          a.   Maintain the Refinery inventory system database on
               process unit meters and tank strapping data for the
               purpose of documentation and reporting of
<PAGE>

                                                                  Schedule 5.8.4
                                                   Services and Supply Agreement

                       Coker Company charges and yields, product inventories and
                       receipts and deliveries including, without limitation,
                       the tracking of product receipt or delivery documentation
                       of marine vessels, pipeline movements, rail cars and
                       deliveries by truck.

                  b.   Provide governmental reporting services for the Coker
                       Company including, without limitation, to the Department
                       of Energy, the American Petroleum Institute, the Bureau
                       of the Census, and the Texas Railroad Commission relative
                       to Heavy Oil Processing Facility production and product
                       movements.

                  c.   Track, reconcile and allocate distributed utilities
                       provided to the Coker Company pursuant to Section 5.5 of
                       the Services and Supply Agreement.

                  d.   Provide specialty reporting including the capture and
                       reporting volumes related to any technology licenses held
                       by the Coker Company or otherwise related to the on-going
                       operation of the Heavy Oil Processing Facility.

     1.5          Foreign Trade Zone

                  Administer all Foreign Trade Zone Subzone activities related
                  to the Heavy Oil Processing Facility including, without
                  limitation, (a) maintaining U.S. Customs Service and Foreign
                  Trade Zone Board Compliance Status, (b) providing weekly,
                  monthly and annual reporting, entries or submissions to the
                  appropriate governmental agencies, (c) maintaining inventory
                  control recordkeeping system records, (d) providing oversight
                  for the operational activities that are required to maintain
                  Foreign Trade Zone Subzone Status for the Heavy Oil Processing
                  Facility and (e) preparing such documentation as required for
                  optimizing Foreign Trade Zone Subzone benefits for the Heavy
                  Oil Processing Facility as required by Applicable Laws.

     1.6          Property Tax Reporting and Management

                  Administer all property tax activities on behalf of the Coker
                  Company, including, without limitation maintaining asset or
                  contractor records for the purpose of filing annual tax
                  renditions and optimizing abatement benefits as required by
                  local, State and Federal laws
 .

2.   Applicable Price.
     ----------------

     The Coker Company shall pay Clark R&M the following fee for providing
     accounting services described in this Schedule: (a) for any month prior to
     and including December 2000, $38,400 and (b) for any month thereafter,
     $38,400, multiplied by the Inflation Factor.
              -------------

                                      -2-
<PAGE>

                                                                  Schedule 5.8.5
                                                   Services and Supply Agreement

                            ADMINISTRATIVE SERVICES

1.   Scope.
     -----

     Administrative and professional personnel from the headquarters office of
     Clark R&M shall perform the following obligations of Clark R&M under the
     Services and Supply Agreement.

     1.1       Refining Support

               a.   Financial Services

                    Assisting the Coker Company accounting manager with
                    preparation of internal and external financial reporting and
                    analysis including, without limitation, providing such
                    accounting manager with information needed to prepare income
                    statements and balance sheets and providing market pricing
                    for yields and inventory and providing working capital
                    management.

               b.   Supply and Trading

                    Negotiation and execution of legal contracts necessary to
                    acquire crude oil and feedstocks to operate the Heavy Oil
                    Processing Facility and coordinating with plant personnel
                    to optimize supply of the Coker Company's requirements of
                    crude oil and feedstocks.

               c.   Emergency, Health & Safety

                    General legal and administrative support of Refinery
                    programs and liaison with governmental agencies that are
                    required for the Coker Company to comply with Applicable
                    Laws and provide guidelines for long-term planning for
                    compliance.

               d.   Executive Management

                    Clark R&M's Chief Operating Officer is responsible for
                    the oversight of profitable operation of the Heavy Oil
                    Processing Facility and shall provide strategic direction
                    that supports operational and organizational variables to
                    assure that resources, processes, and personnel are in
                    place to accomplish the Annual Budget and Operating Plan
                    for the Coker Company.

               e.   Business Development

                    Work with plant personnel that support the optimization
                    of Coker Complex units and the Ancillary Equipment
                    providing analytical support
<PAGE>

                                                                  Schedule 5.8.5
                                                   Services and Supply Agreement

                       and industry benchmark studies and identification of
                       opportunities to optimize asset utilization.

     1.2       Corporate Services

               a.   Income, Franchise, Sales & Use or Property Taxes

                    Responsible for ensuring (i) performance of Clark R&M's
                    obligations under Section 11.7 of the Services and Supply
                    Agreement and (ii) compliance by the Coker Company with all
                    reporting and other requirements of applicable state, local
                    and Federal tax laws.

               b.   General Insurance

                    Responsible for ensuring performance of Clark R&M's
                    obligations under Section 5.13 of the Services and Supply
                    Agreement.

               c.   Information Systems

                    Provide direction and systems support insuring year 2000
                    compliance and technology standards are followed to
                    manage information requirements of the Coker Company.

               d.   Investor and Public Relations

                    Provide specialty reporting and communication to the
                    Securities and Exchange Commission and any necessary
                    Public Notice and Liaison to Investors of the Coker
                    Company Assets.

               e.   Executive Management

                    Clark R&M's Chief Executive Officer and Chief Financial
                    Officer shall be responsible for providing for the
                    support of refining infrastructure to help insure the
                    profitable operation of the Heavy Oil Processing Facility
                    and shall provide strategic direction for financial
                    management and organizational variables to assure that
                    resources, processes, and personnel are in place to
                    accomplish the Annual Budget and Operating Plan for the
                    Coker Company.

               f.   Financial Services

                    Providing information needed by Coker Company for overall
                    consolidation of inter-company agreements for public
                    financial reporting of the Coker Company related to the
                    Heavy Oil Processing Facility.

2.   Applicable Price.
     ----------------
                                      -2-
<PAGE>

                                                                  Schedule 5.8.5
                                                   Services and Supply Agreement

     The Coker Company shall pay Clark R&M the following fee for the
     support services described in this Schedule: (a) for any month prior to and
     including December 2000, $60,000 and (b) for any month thereafter, $60,000,
     multiplied by the Inflation Factor.
     -------------
                                      -3-
<PAGE>

                                                                    Schedule 5.9
                                                   Services and Supply Agreement

                           COKER COMPANY SPARE PARTS

                                     NONE.
<PAGE>

                                                                   Schedule 5.10
                                                   Services and Supply Agreement

                      CATALYST, CHEMICALS AND CONSUMABLES

1.   Scope.
     -----

     1.1.      Coker Complex

               a.    Chemicals and Catalyst

                     Clark R&M shall provide the Coker Company's requirement of
                     chemicals and catalyst including, without limitation, the
                     following (or the commercial equivalent thereof):

<TABLE>
<CAPTION>
            SRU 545            Description                        Estimated Quantity
            -------            -----------                        ------------------
     ---------------------------------------------------------------------------------------------------------
      <S>                      <C>                  <C>
      No. 1 Claus Reactor      Alcoa S-501          117,600 lbs. (density 50lb/ft.3)-4 year life
     ---------------------------------------------------------------------------------------------------------
      No. 2 Claus Reactor      Alcoa S-201          108,200 lbs. (density 46 lb/ft.3)-4 year life
     ---------------------------------------------------------------------------------------------------------
      No. 3 Claus Reactor      Alcoa S-201          108,200 lbs. (density 46 lb/ft.3)-4 year life
     ---------------------------------------------------------------------------------------------------------
      SCOT Catalyst            Criterion 534        75,000 lbs (density 47 lb/ft.3)-4 year life
     ---------------------------------------------------------------------------------------------------------
      Amine Solvent            Huntsman MDEA        183,600 pounds (45% concentration) inventory
                                                    unit
                                                    10,000 lbs./year make-up, (0.8 lbs/MMSCF of
                                                    treated gas)
      BFW Polymer              Betz AP 0200         500 gallons
      BFW O2 Scavenger         Betz OS 2001         500 gallons
     ---------------------------------------------------------------------------------------------------------
      BFW Neutralizing         Betz NA 2440         500 gallons
      amine

<CAPTION>
            ATU 7841           Description                        Estimated Quantity
            --------           -----------                        ------------------
     ---------------------------------------------------------------------------------------------------------
      <S>                    <C>                    <C>
      Amine Solvent          Huntsman MDEA          1.1 million pounds (45% concentration) to
                                                    inventory unit

<CAPTION>
            DCU 843            Description                        Estimated Quantity
            -------            -----------                        ------------------
     ---------------------------------------------------------------------------------------------------------
      <S>                      <C>                  <C>
      Silica Removal           Alumina Based        160,000 lbs (density 36.4 lb/ft.3) once per year
      Reactor                     Only
     ---------------------------------------------------------------------------------------------------------
      Di-olefin Reactor        Ni-Mo Alumina        30,000 lbs. (density 37.5 lb/ft.3) every two years
                                  Based
     ---------------------------------------------------------------------------------------------------------
      Amine Solvent            Huntsman MDEA        164,000 pounds (45% concentration) to inventory
                                                    unit.
                                                    79,000 lbs./year make-up, (0.8 lbs./mmscf of
                                                    treated gas and 0.8 lbs./1,000 gals., circulating
                                                    treated liquid)
      Caustic                  US Filter ARI-       190 Pounds per hour
      Regeneration           100L or ARI-100
      catalyst                     EXL
     ---------------------------------------------------------------------------------------------------------
      Antifoam Silicon         Betz Antifoam        2,000 gallons per year (2,000 gallon tank)
     ---------------------------------------------------------------------------------------------------------
      De-emulsifier            Betz De-emulsifier   3,250 gallons per year (500 gallon tote tank)
     ---------------------------------------------------------------------------------------------------------
</TABLE>
<PAGE>

                                                                   Schedule 5.10
                                                   Services and Supply Agreement

<TABLE>
<CAPTION>
            HCU 942            Description                        Estimated Quantity/1/
            -------            -----------                        ---------------------
     ---------------------------------------------------------------------------------------------------------
     <S>                      <C>                     <C>
      Chevron Catalyst           SA 5517              6,000 pounds - every two years
     ---------------------------------------------------------------------------------------------------------
      Chevron Catalyst       ICR 122 Z5B              15,600 pounds - every two years
     ---------------------------------------------------------------------------------------------------------
      Chevron Catalyst       ICR 132 NAQ              19,500 pounds - every two years
     ---------------------------------------------------------------------------------------------------------
      Chevron Catalyst       ICR 135 KAQ              16,200 pounds - every two years
     ---------------------------------------------------------------------------------------------------------
      Chevron Catalyst       ICR 141 L32              88,200 pounds - every two years
     ---------------------------------------------------------------------------------------------------------
      Chevron Catalyst       ICR 141 L34              333,000 pounds - every two years
     ---------------------------------------------------------------------------------------------------------
      Chevron Catalyst       ICR 141 L38              108,000 pounds - every two years
     ---------------------------------------------------------------------------------------------------------
      Chevron Catalyst       ICR 154 KF               97,200 pounds - every two years
     ---------------------------------------------------------------------------------------------------------
      Chevron Catalyst        ICR 210L                93,500 pounds - every two years
     ---------------------------------------------------------------------------------------------------------
      Chevron Catalyst       ICR 114 ZF               45,900 pounds - every two years
     ---------------------------------------------------------------------------------------------------------
      Amine Solvent       Huntsman MDEA               270,000 pounds (45% concentration) to inventory
                                                      unit
                                                      3,600 lbs./year make-up, (0.8 lbs./mmscf of
                                                      treated gas).
     ---------------------------------------------------------------------------------------------------------
      Catalyst Treatment     Tri Butyl Amine          12,300 gallons every two years
     ---------------------------------------------------------------------------------------------------------
      Catalyst Treatment     Di-Methy Di-Sulfide      120,000 pounds every two years
     ---------------------------------------------------------------------------------------------------------
</TABLE>

1.   The catalyst amounts listed include an additional 5% contingency and have
been rounded to the nearest whole drum or sack. These amounts will be precisely
defined upon loading the reactors.

               b.   Caustic

                    Clark R&M shall provide the Coker Company's requirement of
                    fresh caustic necessary for treatment of the Coker C3/C4
                    stream and shall provide for the disposal of spent caustic
                    from the Coker.

                                      -2-
<PAGE>

                                                                   Schedule 5.10
                                                   Services and supply Agreement

                  The expected specifications of fresh caustic to be supplied
                  by Clark R&M are described in the following table:

                           Fresh Caustic Properties

                  Component               Element      Basis   Specification
                  ------------------  ---------------  ------  -------------
                  Sodium Oxide        Na\\2\\O           %        38.0 - 39.5
                  Sodium Hydroxide    NaOH               %        49.00 - 51.0
                  Sodium Chloride     NaCl               %        1.10 Max
                  Sodium Carbonate    Na\\2\\CO\\3\\     %        0.20 Max
                  Sodium Sulfate      Na\\2\\SO\\4\\     %        0.05 Max
                  Sodium Chlorate     NaClO\\3\\         %        0.30 Max
                  Iron                Fe                ppm       10 Max

                  The following are the expected qualities of spent caustic from
                  the Coker:

                           Spent Caustic Properties

                  Component           Element              Basis    Composition
                  ---------           -------              -----    -----------
                  Water               H\\2\\O              Wt. %    82.8
                  Sodium Hydroxide    NaOH                 Wt. %    6.9
                  Sodium Thiosulfate  Na\\2\\S\\2\\O\\3\\  Wt. %    5.2
                  Sodium Carbonate    Na\\2\\CO\\3\\       Wt. %    5.1
                  Di-Sulfide Oil      DSO                  Wt. %    Trace

     1.2     Ancillary Equipment

             Clark R&M shall provide all chemicals, catalyst, caustic and
             other consumables required for the on-going operation of the
             Ancillary Equipment.

2.   Metering/Measurement Method for Supply to the Coker Complex.
     -----------------------------------------------------------

     2.1     Chemicals and Catalyst

             The amount of catalyst or chemicals supplied to the Coker Company
             for use at the Coker Complex each month shall be the amount of such
             catalyst or chemicals actually purchased by Clark R&M in such month
             for use in Coker Complex units.

     2.2     Caustic

                                      -3-
<PAGE>

                                                                   Schedule 5.10
                                                   Services and Supply Agreement

             The actual amount of fresh caustic supplied to the Coker Company
             each month for use at the Coker Complex shall be measured by
             gauging Tank 6790 located on DCU 843 each time fresh caustic is
             received from the fresh caustic system at the Refinery.

3.   Applicable Price.
     ----------------

     3.1     Coker Complex

             a.   Chemicals and Catalyst

                  The Coker Company shall reimburse Clark R&M for all Permitted
                  Reimbursable Expenses incurred each month by Clark R&M in
                  providing chemicals and catalyst to the Coker Complex.

             b.   Caustic

                  The Coker Company shall pay Clark R&M for fresh caustic
                  supplied to the Coker Complex each month according to the
                  following formula:

                        Average Monthly Refinery Caustic Cost * Monthly Coker
                        Complex Usage

                  Where:

                        "Average Monthly Refinery Caustic Cost" means, for any
                        month (a) the actual costs incurred by Clark R&M in
                        purchasing, blending and delivering caustic for all
                        Refinery units in such month, divided by (b) the
                                                      ----------
                        total volume of caustic supplied to Refinery units
                        in such month.

                        "Monthly Coker Complex Usage" means, for any month, the
                        metered usage of caustic by the Coker Complex units in
                        such month.

                  Consideration for disposal of spent caustic by Clark R&M is
                  included in the fees payable under Schedule 5.6 (Waste
                  Management and Waste Water Services)

     3.2     Ancillary Equipment

             Consideration for chemicals, catalyst, caustic and other
             consumables provided by Clark R&M for the operation of the
             Ancillary Equipment is provided for in the Ancillary Equipment
             Operating Fee.

                                      -4-
<PAGE>

                                                                 Schedule 5.12.1
                                                   Services and Supply Agreement

               ENVIRONMENTAL, HEALTH AND SAFETY SERVICES

1.   Scope.
     -----

     1.1       Safety

               Clark R&M shall provide safety and industrial hygiene support to
               the Coker Company including, without limitation, safety
               procedures, hygiene monitoring, injury recordkeeping, mandatory
               employee training incident investigation, monitoring of
               operations, OSHA and Texas Department of Health compliance
               planning and budgeting, government agency liaisons during
               inspections, enforcement actions and hearings, acquisition of all
               required Permits and licenses, implementation and maintenance of
               a structured safety process including internal audits and
               inspections.

     1.2       Process Safety Management ("PSM")

               Clark R&M shall provide overall OSHA PSM compliance coordination
               and oversight services for the Heavy Oil Processing Facility and
               shall implement and maintain a structured PSM compliance program
               that addresses (a) employee participation, (b) process safety
               information, (c) process hazard analysis, (d) operating
               procedures, (e) training, (f) contractor safety, (g) pre-start up
               safety review, (h) mechanical integrity of units, (i) "hot work"
               Permits, (j) management of change, (k) incident investigation,
               (l) emergency planning and response, (m) compliance audits and
               (o) trade secrets.

     1.3       Environmental

               Clark R&M shall provide environmental compliance coordination and
               oversight services for the Heavy Oil Processing Facility
               including, without limitation, regulatory and legislative
               tracking, compliance planning and budgeting necessary to meet
               current and future Environmental Protection Agency, Texas Natural
               Resource Conservation Commission, Department of Transportation
               and U.S. Coast Guard rules and regulations, mandatory employee
               training, securing Permits and licenses, arranging for
               performance tests, analyses and other measurements required by
               Applicable Law, handling recordkeeping and reporting, providing
               government agency liaisons during inspections, enforcement
               actions and hearings and internal inspections and internal
               audits.

2.   Applicable Price.
     ----------------

     2.1  Coker Complex

               a.  The Coker Company shall pay Clark R&M the following fee for
                   providing environmental, health and safety services the Coker
                   Company related to the Coker Complex each month: (i) for any
                   month prior to and
<PAGE>

                                                                 Schedule 5.12.1
                                                   Services and Supply Agreement

                   including December 2000, $22,900 and (ii) for any month
                   thereafter, $22,900, multiplied by the Inflation Factor
                                        -------------

               b.  The Coker Company shall pay, or reimburse Clark R&M for, all
                   fees in connection with the procurement or renewal of any
                   Permits or other governmental approvals related solely to the
                   operation of the Coker Complex or the existence of the Coker
                   Company.

     2.2  Ancillary Equipment

          Consideration for environmental, health and safety services provided
          by Clark R&M in connection with the operation of the Ancillary
          Equipment is provided for in the Ancillary Equipment Operating Fee.

                                      -2-
<PAGE>

                                                                 Schedule 5.12.2
                                                   Services and Supply Agreement

                          EMERGENCY RESPONSE SERVICES

1.   Scope.
     -----

            1.1   General

                  a.   Clark R&M shall maintain and operate (i) the underground
                       piping and distribution system, pumping system, post
                       indicator valves, hydrants, fire monitors, deluge systems
                       and related equipment for the purpose of delivering Fire
                       Water (as defined below) throughout the Refinery (the
                       "Fire Water System") and (ii) medical response equipment,
                       hazardous release equipment, spill response equipment,
                       fire trucks, ambulances, hazmat vans, communications
                       vans, extinguishers, hose carts, self-contained breathing
                       apparatus ("SCBA") equipment and other equipment
                       necessary or desirable to respond to emergencies at the
                       Refinery (together with the Fire Water System, "Emergency
                       Response Equipment").

                  b.   Clark R&M shall supply the Coker Company with raw water
                       that has been pumped into the Fire Water System to a
                       nominal pressure of 100 psig ("Fire Water") for fire
                       control and other purposes.

                  c.   Clark R&M shall flush the Fire Water System main as
                       necessary to maintain and inspect the system.

                  d.   Clark R&M shall conduct performance tests of the fire
                       pumps at least annually.

                  e.   Clark R&M shall develop and implement an emergency
                       response plan for the Coker Complex.

                  f.   Clark R&M shall maintain and repair the following fixed
                       and portable Emergency Response Equipment to be located
                       at the Coker Complex.

                  i.   hand portable extinguishes (dry chemical)
                  ii.  hose cam - annual hydrostatic test for hoses
                  iii. fire mains, post indicator valves, hydrants and monitors
                  iv.  SCBA equipment

                  g.   Clark R&M shall maintain all Emergency Response Equipment
                       in accordance with the manufacturers' service schedule
                       and repair it in accordance with recommended practices.
                       Maintenance of such equipment shall include lubricating
                       and replacing parts to the fire trucks, ambulances,
                       hazmat vans, communications vans and other vehicles.
<PAGE>

                                                                 Schedule 5.12.2
                                                   Services and Supply Agreement

                 h.   Clark R&M shall calibrate, maintain and repair all gas
                      detection equipment located in the Coker Complex in
                      accordance with the manufacturers' service schedule and
                      repair it in accordance with recommended practices.

            1.2  Emergency Response Team

                 a.   Clark R&M shall designate a "Fire Chief" who shall be
                      responsible for managing the Coker Company's emergency
                      response plan, and for general management of any
                      emergency. Each party shall cooperate in maintaining a
                      plant emergency response team who shall perform the duties
                      set forth in the emergency response plan including,
                      without limitation, the following:

                      i.   response to alarms and other emergency calls
                      ii.  response to medical emergencies, hazardous chemical
                           releases and rescue situations
                      iii. attending regularly scheduled emergency drills
                      iv.  performance Fire Water System main flushing
                      v.   attending quarterly group training sessions as
                           scheduled by the Fire Chief

                 b.   The Fire Chief shall train and effectively implement the
                      emergency response plan with the team. In addition, Clark
                      R&M will review with Coker Company or provide additional
                      training to Coker Company employees to ensure proper
                      coordination of emergency response plan. All emergency
                      response team members must meet minimum standards
                      specified by Applicable Law.

                 c.   The emergency response team shall consist of the following
                      minimum complement of personnel per shift unless otherwise
                      decided by Clark R&M or Applicable Law:

                      i.   2 Fire Mechanics from Clark R&M
                      ii.  8 Brigade Members from Clark R&M
                      iii. 2 Brigade Members from Coker Company

                 d.   Emergency response team members shall be issued car passes
                      to allow entry into the Refinery or the Coker Complex
                      property.

          1.3    Emergency Communications

                 Clark R&M shall maintain the Refinery radio emergency channel
                 equipment and the refinery-wide emergency alarm and
                 notification system (beeper) in good operating condition and
                 provide the Coker Company with access to all emergency
                 communications equipment at the Refinery.

                                      -2-
<PAGE>

                                                                 Schedule 5.12.2
                                                   Services and Supply Agreement

2.   Applicable Price.
     ----------------

     2.1  Coker Complex

          a.  The Coker Company shall reimburse Clark R&M for the actual cost of
              materials used by Clark R&M in maintaining and repairing Emergency
              Response Equipment (including the Fire Water System) for the Coker
              Complex during each month and for the actual cost for materials
              actually used by Clark R&M in responding to and emergency
              situations at the Coker Complex.

          b.  The Coker Company shall pay Clark R&M a monthly fee of $10,000 for
              all other emergency response services provided to the Coker
              Company by Clark R&M.

          c.  Each party shall bear its own Labor Costs incurred with respect to
              its own employees, including emergency response team members, who
              may be involved in performing emergency response services
              hereunder.

     2.2      Ancillary Equipment

              Consideration for emergency response services provided by Clark
              R&M to the Coker Company related to the Ancillary Equipment is
              provided for in the Ancillary Equipment Operating Fee.

                                      -3-
<PAGE>

                                                                   Schedule 5.13
                                                    Service and Supply Agreement

                                   INSURANCE

1.   Scope of Coverages.
     ------------------

     1.1    Coker Company Insurance

            Clark R&M shall cause the insurance coverages listed under the
            headings "Construction Period -- Partnership" and "Operational
            Period--Partnership" on Exhibit J to the Common Security Agreement
            to be maintained in the name of the Coker Company in accordance with
            the provisions of such Exhibit and Article 7 of the Common Security
            Agreement.

     1.2    Clark R&M shall provide and maintain the insurance coverages listed
            under the headings "Construction Period -- Operator" and
            "Operational Period -- Operator" on Exhibit J to the Common Security
            Agreement to be maintained in its name in accordance with the
            provisions of such Exhibit and Article 7 of the Common Security
            Agreement.

2.   Applicable Price.
     ----------------

     2.1.   Consideration for obtaining and maintaining insurance is included in
            the fees payable under Schedule 5.8.5.

     2.2    The Coker Company shall pay directly, or reimburse Clark R&M for
            payment of, premiums, fees or deductibles payable in connection with
            the insurance coverages described in 1.1 above.

     2.3    Consideration for maintenance of the insurance coverages described
            in 1.2 above is included in the Ancillary Equipment Operating Fee.
<PAGE>

                                                                   Schedule 5.14
                                                    Service and Supply Agreement

                       LICENSING, PERMITS AND APPROVALS

1.   Scope.
     -----

     1.1.   Licenses, Permits and Approvals held by Clark R&M

            a.   Federal Communications Commission 800 megahertz license for the
                 Trunked Radio System (as such term is defined on Schedule
                 5.7.3)

            b.   AIR EMISSION PERMITS FROM TEXAS NATURAL RESOURCE CONSERVATION
                 COMMISSION ("TNRCC")

                 i.    TNRCC No.6825A/PSD 49  -- Flexible Permit

                       Covering the Marine docks for feed receipts, product &
                       coke shipping, Refinery Units, Tanks, boilers, flares.

                 ii.   TNRCC No. 7600 -- Crude Tanks
                 iii.  TNRCC No. 802  -- Gas Turbine Generator
                 iv.   TNRCC No. 5491 -- Crude Tanks
                 v.    TNRCC No.  8369 -- Amine Treating
                 vi.   TNRCC No. 4478
                       TNRCC No. 1535
                       TNRCC No. 7585

                             Crude Tanks at  Lucas
                            Product Tanks at Lucas

            c.   WATER PERMITS - (Federal & State)

                 i.    Wastewater Discharge NPDES No. TX 0005991
                 ii.   Wastewater Discharge TNRCC No.  00309
                 iii.  Wastewater Permit Expansion Wavier

                 iv.   TNRCC Stormwater Discharge- LUCAS
                 v.    TNRCC Water Rights Adudification Certificate-FANNETT

            d.   WASTE MANAGEMENT PERMITS

                 i.    TNRCC Solid Waste Notice of Registration No. 30004
                 ii.   EPA Hazardous Waste Generator Permit
                 iii.  EPA  PCB Waste Generator Permit
                 iv.   TNRCC Solid Waste Notice of Registration - LUCAS
                 v.    EPA Hazardous Waste Generator I.D. No.- LUCAS
                 vi.   Railroad Commission of Texas Brine Disposal Permit-
                       Fannett

            e.   OPERATING  PERMITS

<PAGE>

                                                                   Schedule 5.14
                                                    Service and Supply Agreement

                 i.    Corps of Engineers Pipeline Operating Permit 217
                 ii.   Corps of Engineers Pipeline Operating Permits 218
                 iii.  Corps of Engineers Pipeline Operating Permits 219
                 iv.   Railroad Commission of Texas Salt Dome Permit
                 v.    Railroad Commission of Texas Brine Pit Permit

     1.2    Licenses, Permits and Approvals held by Coker Company

            a.   Air Emissions Permit TNRCC No. 2303A

                 Authorization to construct the Coker Complex covering the
                 following:

                       DCU 843
                       HCU 942
                       SRU 545
                       SWS 8747
                       Flare 23
                       Crude Oil Tanks 106 - 109 (Four Total)

            b.   Standby Air Emissions Permit No. 6825Z/PSD - TX - 492

2.   Applicable Price.
     ----------------

     Consideration for obtaining and maintaining Permits is included in the fees
     payable under Schedule 5.12.1.

                                      -2-
<PAGE>

                                                                    Schedule 6.1
                                                   Services and Supply Agreement

                       ANNUAL BUDGET AND OPERATING PLAN

--------------------------------------------------------------------------
INCOME STATEMENT
                                     -------------------------------------
                                                     2001
                                     -------------------------------------
                                       Q1        Q2        Q3        Q4
                                       --        --        --        --

Total Product Revenue                $263.5    $298.5    $289.5    $298.7
Total Chargestock Cost                203.6     234.2     233.6     231.9
                                     ------    ------    ------    ------
     Refinery Gross Margin             59.9      64.4      55.9      66.8
                                         -         -         -         -
Margin Stabilization                   12.1       6.1      15.2      10.4
                                     ------    ------    ------    ------

     Total Gross Margin                72.1      70.4      71.1      77.2

Variable Operating Expenses             6.3       6.5       6.9       6.8
Fixed Operating Expenses                8.6       8.6       8.6       8.6
Lease Fees                              8.5       8.6       8.7       8.7
Operating Fees                         13.2      13.0      13.0      14.0
Processing Fees                       (17.1)    (17.3)    (17.4)    (17.7)
G&A Expense                             0.2       0.2       0.2       0.2
                                     ------    ------    ------    ------
     Total Expenses                    19.6      19.6      20.0      20.5
     EBITDA                            52.4      50.8      51.0      56.6

Amortization                             -         -         -         -
Depreciation                            2.9       2.9       2.9       2.9
                                     ------    ------    ------    ------
     EBIT                              49.5      47.9      48.1      53.7

Interest Expense, Net                  16.4      18.3      14.7      16.4
                                     ------    ------    ------    ------

Net Income                             33.1      29.6      33.5      37.3
<PAGE>

                                                                    Schedule 6.1
                                                   Services and Supply Agreement

GROSS MARGIN ASSUMPTIONS

<TABLE>
<CAPTION>
                                                 -------------------------------------------------
                                                                        2001
                                                 -------------------------------------------------
                                                     Q1           Q2           Q3             Q4
                                                     --           --           --             --
<S>                                              <C>          <C>          <C>            <C>
Products - Volume ('000 bpd)

     DISTILLATES
          LS Diesel                                  36.7         38.8         38.8           38.8
          Jet Fuel                                   24.2         25.5         25.5           25.5
                                                 --------     --------     --------       --------
          SUBTOTAL - Distillates                     60.9         64.3         64.3           64.3

     LPG
          Propane                                     1.0          1.1          1.1            1.1
          Isobutane                                   0.3          0.4          0.4            0.4
          Normal Butane                               2.0          2.1          2.1            2.1
                                                 --------     --------     --------       --------
          SUBTOTAL - LPG                              3.4          3.6          3.6            3.6

     UNFINISHED
          Coker Propane Propylene Mix                 2.0          2.1          2.1            2.1
          Coker Butane Butylene Mix                   1.4          1.5          1.5            1.5
          Penhex                                      8.7          9.2          9.2            9.2
          Virgin Diesel                               7.1          7.4          7.4            7.4
          Naphtha - Sour                             33.1         35.0         35.0           35.0
          Heavy Naphtha                               3.6          3.8          3.8            3.8
          ULS VGO                                     9.7         10.3         10.3           10.3
          VGO                                        41.9         44.2         44.2           44.2
                                                 --------     --------     --------       --------
          SUBTOTAL - Unfinished                     107.5        113.4        113.4          113.4

     OTHER PRODUCTS
          Sulfur                                      1.2          1.2          1.2            1.2
          Coke                                       17.2         18.2         18.2           18.2
          Produced Fuel                               4.0          4.4          4.5            4.4
                                                 --------     --------     --------       --------
          SUBTOTAL - Other Products                  22.4         23.8         23.9           23.8
                                                 --------     --------     --------       --------
      TOTAL PRODUCTS                                194.1        205.1        205.1          205.1
                                                 ========     ========     ========       ========
</TABLE>

                                      -2-
<PAGE>

                                                                    Schedule 6.1
                                                   Services and Supply Agreement

GROSS MARGIN ASSUMPTIONS
------------------------

<TABLE>
<CAPTION>
                                                                    2001
                                                ------------------------------------------------
                                                    Q1            Q2            Q3          Q4
                                                    --            --            --          --
<S>                                             <C>            <C>           <C>         <C>
Chargestock - Volume ('000 bpd)
-------------------------------
     CRUDE
     -----
          Arab Lt.                                  36.2          38.2          38.2        38.2
          --------                               -------       --------      -------     -------
          Maya - Market                            144.8         152.9         152.9       152.9
          -------------                          -------       --------      -------     -------

          SUBTOTAL - Crude                         181.0         191.1         191.1       191.1
          ----------------                       =======       ========      =======     =======

      OTHER CHARGESTOCKS
      ------------------
          GFU Feed                                   1.5           1.5           1.5         1.5
          ---------                              -------       -------       -------     -------
          Hydrogen                                   3.2           3.4           3.4         3.4
          --------                               -------       -------       -------     -------

          SUBTOTAL - Other Chargestocks              4.7           4.9           4.9         4.9
          -----------------------------          -------       -------       -------     -------

     TOTAL CHARGESTOCK                             185.7         196.0         196.0       196.0
     -----------------                           =======       =======       =======     =======
</TABLE>

                                      -3-
<PAGE>

                                                                    Schedule 6.1
                                                   Services and Supply Agreement

GROSS MARGIN ASSUMPTIONS
------------------------

<TABLE>
<CAPTION>
                                                                     2001
                                                 -----------------------------------------------
                                                     Q1            Q2            Q3          Q4
                                                     --            --            --          --
<S>                                              <C>           <C>           <C>         <C>
Products - Price ($/bbl)
-----------------------

     DISTILLATES
     -----------
          LS Diesel                                18.65         18.64         18.52       19.95
          ---------                              -------       -------       -------     -------
          Jet Fuel                                 18.92         18.90         19.18       20.80
          --------                               -------       -------       -------     -------

     LPG
     ---
          Propane                                  11.48         11.63         11.42       12.13
          -------                                -------       -------       -------     -------
          Isobutane                                14.82         15.67         14.94       15.09
          ---------                              -------       -------       -------     -------
          Normal Butane                            13.24         11.27         11.11       14.17
          -------------                          -------       -------       -------     -------

     UNFINISHED
     ----------
          Coker Propane Propylene Mix              13.30         13.99         14.03       14.45
          ---------------------------            -------       -------       -------     -------
          Coker Butane Butylene Mix                14.30         17.48         15.47       14.40
          ---------------------------            -------       -------       -------     -------
          Penhex                                   13.24         16.44         14.56       13.20
          ------                                 -------       -------       -------     -------
          Virgin Diesel                            16.69         16.79         16.74       18.32
          -------------                          -------       -------       -------     -------
          Naphtha - Sour                           16.26         18.42         16.93       16.61
          --------------                         -------       -------       -------     -------
          Heavy Naphtha                            19.03         21.18         19.70       19.37
          -------------                          -------       -------       -------     -------
          ULS VGO                                  17.21         18.64         17.49       17.59
          -------                                -------       -------       -------     -------
          VGO                                      15.06         16.44         15.37       15.42
          ---                                    -------       -------       -------     -------

     OTHER PRODUCTS
     --------------
          Sulfur                                    9.38          9.40          9.43        9.46
          ------                                 -------       -------       -------     -------
          Coke                                     (0.26)        (0.19)        (0.11)      (0.11)
          ----                                   -------       -------       -------     -------
          Produced Fuel                            13.15         11.87         11.71       13.34
          -------------                          -------       -------       -------     -------
</TABLE>

                                      -4-
<PAGE>

                                                                    Schedule 6.1
                                                   Services and Supply Agreement

GROSS MARGIN ASSUMPTIONS
------------------------
                                                         2001
                                          ------------------------------------
                                             Q1      Q2       Q3       Q4
                                             --      --       --       --
Chargestocks - Price ($/bbl)
----------------------------
     CRUDE
     -----
       Arab Lt.                         14.27  15.15  14.81  15.06
       --------                         -----  -----  -----  -----

       Maya - Market                    11.22  12.26  12.13  11.86
       -------------                    -----  -----  -----  -----

     OTHER CHARGESTOCKS
     ------------------
       GFU Feed                         16.68  16.78  16.73  18.31
       --------                         -----  -----  -----  -----

       Hydrogen                         30.04  27.61  27.30  30.40
       --------                         -----  -----  -----  -----

                                               Q1      Q2       Q3       Q4
                                               --      --       --       --
     DISTILLATES
     -----------
       LS Diesel                            $ 61.6   $ 65.8   $ 66.1   $ 71.2
       ---------                            ------   ------   ------   ------
       Jet Fuel                               41.1     43.8     45.0     48.8
       --------                              -----    -----    -----    -----
       SUBTOTAL - Distillates                102.8    109.6    111.0    119.9
       ----------------------                -----    -----    -----    -----

     LPG
     ---
       Propane                                1.1      1.2      1.2       1.2
       -------                              -----    -----    -----     -----
       Isobutane                              0.4      0.5      0.5       0.5
       ---------                            -----    -----    -----     -----
       Normal Butane                          2.4      2.2      2.2       2.8
       -------------                        -----    -----    -----     -----
       SUBTOTAL - LPG                         3.9      3.9      3.8       4.5
       --------------                       -----    -----    -----     -----

     UNFINISHED
     ----------
       Coker Propane Propylene Mix            2.4      2.7      2.7       2.8
       ---------------------------          -----    -----    -----     -----
       Coker Butane Butylene Mix              1.8      2.4      2.1       2.0
       -------------------------            -----    -----    -----     -----
       Penhex                                10.4     13.8     12.3      11.2
       ------                               -----    -----    -----     -----
       Virgin Diesel                         10.6     11.4     11.5      12.6
       -------------                        -----    -----    -----     -----
       Naphtha - Sour                        48.5     58.6     54.4      53.4
       --------------                       -----    -----    -----     -----
       Heavy Naphtha                          6.1      7.2      6.8       6.7
       -------------                        -----    -----    -----     -----
       ULS VGO                               15.1     17.4     16.5      16.6
       -------                              -----    -----    -----     -----
       VGO                                   56.7     66.1     62.5      62.7
       ---                                  -----    -----    -----     -----
       SUBTOTAL - Unfinished                151.6    179.6    168.9     167.9
       ---------------------                -----    -----    -----     -----

     OTHER PRODUCTS
     --------------
       Sulfur                                 1.0      1.1      1.1       1.1
       ------                              ------   ------   ------    ------
       Coke                                  (0.4)    (0.3)    (0.2)     (0.2)
       ----                                ------   ------   ------    ------
       Produced Fuel                          4.7      4.8      4.8       5.4
       -------------                       ------   ------   ------    ------
       SUBTOTAL - Other Products              5.3      5.5      5.7       6.3
       -------------------------           ------   ------   ------    ------
     TOTAL PRODUCT REVENUE                 $263.5   $298.5   $289.5    $298.7
     ---------------------                 ------   ------   ------    ------
                                                          2001
                                           ---------------------------------
                                               Q1      Q2       Q3       Q4
                                               --      --       --       --
GROSS MARGIN ASSUMPTIONS
------------------------

                                      -5-
<PAGE>

                                                                    Schedule 6.1
                                                   Services and Supply Agreement

Chargestock Cost ($ in millions)
---------------------------------
     CRUDE
     -----
       Arab Lt.                           $ 46.5   $ 52.7   $ 52.1   $ 52.9
       --------                           ------   ------   ------   ------
       Maya - Market                       146.2    170.6    170.6    166.8
       -------------                      ------   ------   ------   ------
       SUBTOTAL - Crude                    192.7    223.3    222.6    219.8
       ----------------                   ------   ------   ------   ------

     OTHER CHARGESTOCKS
     ------------------
       GFU Feed                              2.2      2.3      2.4      2.6
       --------                           ------   ------   ------   ------
       Hydrogen                              8.7      8.6      8.6      9.5
       --------                           ------   ------   ------   ------
       SUBTOTAL - Other Chargestocks        10.9     10.9     10.9     12.1
       --------------------------------------------------   ------   ------

     TOTAL CHARGESTOCK COST               $203.6   $234.2   $233.6   $231.9
     ----------------------               ======   ======   ======   ======

     TOTAL PRODUCT GROSS MARGIN           $ 59.9   $ 64.4   $ 55.9   $ 66.8
     ----------------------------------------------------   ------   ------

                                      -6-
<PAGE>

                                                                    Schedule 6.1
                                                   Services and Supply Agreement

--------------------------------------------------------------------------------
VARIABLE & FIXED OPERATING EXPENSE
----------------------------------

<TABLE>
<CAPTION>
                                       2001
                                    ---------------------------------
                                       Q1      Q2      Q3      Q4
                                       --      --      --      --
<S>                                 <C>      <C>      <C>     <C>
Variable ($ in millions)
============================

Fuel Consumed                        $  3.7  $  3.5   $  3.5  $  4.0
-------------                       -------  ------   ------  -------

Electricity                          $  2.4  $  2.7   $  3.2  $  2.5
-----------                         -------  ------   ------  -------
Other                                   0.2     0.2      0.2     0.2
-----                               -------  ------   ------  -------
Total Variable expenses                 6.3     6.5      6.9     6.8
-----------------------             -------  ------   ------  -------

Fixed ($ in millions)
============================

Operating labor                         2.8     2.8      2.8     2.8
---------------                     -------  ------   ------  -------

Cat / Chemicals                         1.1     1.1      1.1     1.1
---------------                     -------  ------   ------  -------

Repairs & Maintenance                   1.8     1.8      1.8     1.8
---------------------               -------  ------   ------  -------

Environmental                           0.2     0.2      0.2     0.2
-------------                       -------  ------   ------  -------

Insurance                               0.5     0.5      0.5     0.5
---------                           -------  ------   ------  -------

Taxes                                   1.0     1.0      1.0     1.0
-----                               -------  ------   ------  -------

Other                                   1.2     1.2      1.2     1.2   Contingency
-----                               -------  ------   ------  -------  -----------

Total Fixed Operating expenses       $  8.6   $ 8.6   $  8.6  $  8.6
------------------------------      -------  ------   ------  -------

Total Operating expenses               14.9    15.1     15.5    15.3
------------------------            -------  ------   ------  -------

Processing Fees Paid to Clark           4.6     4.4      4.4     5.0
-----------------------------       -------  ------   ------  -------
Contract Services                       0.4     0.4      0.4     0.4
-----------------                   -------  ------   ------  -------
G&A Allocation                          0.2     0.2      0.2     0.2
--------------                      -------  ------   ------  -------

Summary used to calculate accounts
----------------------------------
 payable for operating expenses        30.0    30.3     30.9    31.2
-------------------------------------------  ------   ------  -------
</TABLE>

Variable ($/bbl crude charge)
===================================

                                      -7-
<PAGE>

                                                                    Schedule 6.1
                                                   Services and Supply Agreement

<TABLE>
<S>                                               <C>          <C>
Fuel                                                 0.00         0.00
----                                              -------      -------

Electricity                                          0.00         0.00
-----------                                       -------      -------

Steam                                                   -            -
-----                                             -------      -------

Other                                                   -            -
-----                                             -------      -------

Total Variable expenses ($/bbl crude)   0.00                      0.00
--------------------------------------------                   -------

Total Variable expenses ($)                        $ 0.00       $ 0.00
---------------------------                       =======      =======

Fixed ($/bbl crude charge)
============================================

Operating labor                                      0.00         0.00
---------------                                   -------      -------

Cat / Chemicals                                      0.00         0.00
---------------                                   -------      -------

Maintenance/Environmental                            0.00         0.00
-------------------------                         -------      -------

                                                     0.00         0.00
                                                  -------      -------

Taxes & insurance                                    0.00         0.00
-----------------                                 -------      -------

Total fixed expenses ($/bbl crude)
----------------------------------

Total Fixed expenses ($)                           $ 0.00       $ 0.00
------------------------                          =======      =======

                                                   $ 0.00       $ 0.00
                                                  -------      -------
</TABLE>

                                      -8-
<PAGE>

                                                                    Schedule 6.1
                                                   Services and Supply Agreement

<TABLE>
<CAPTION>
                                                      2001
                                        ------------------------------
                                          Q1       Q2      Q3       Q4
                                          --       --      --       --
<S>                                     <C>        <C>     <C>    <C>
License Fees (Cash)                                                0.9
-------------------                                               ----
License Fees (Expense)
----------------------

Catalyst Chemicals (Cash)
-------------------------
Catalyst Chemicals (Expense)              0.7     0.7      0.7     0.7
----------------------------            -----    ----     ----    ----
Total Cat & Chem Expense                  1.1     1.1      1.1     1.1
------------------------                -----    ----     ----    ----

Amortized Financing Charges                 -     2.4        -     2.2
---------------------------             -----    ----     ----    ----
</TABLE>

HDS Catalyst
------------
Diolifin Catalyst
-----------------
SCOTT Catalyst
--------------
HKG Catalyst
------------
SRU Catalyst
------------

                                      -9-
<PAGE>

                                                                       EXHIBIT A
                                                   Services and Supply Agreement

                                   TABLE V-9
                        PORT ARTHUR COKER COMPANY L.P.
                                   BASE CASE
                              CHARGES AND YIELDS

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

<TABLE>
<CAPTION>
                                              2001     2002     2003     2004     2005     2006      2007     2008
                                             -----    -----    -----    -----    -----    -----     -----    -----
<S>                                          <C>      <C>      <C>      <C>      <C>      <C>       <C>      <C>
Products - Volume (bpd in thousands)
  DISTILLATES
    LS Diesel                                 38.3     40.6     40.8     38.5     40.8     40.6      40.8     38.5
    Jet Fuel                                  25.2     26.3     26.8     25.3     26.8     26.3      26.8     25.3
                                             -----    -----    -----    -----    -----    -----     -----    -----
    SUBTOTAL - Distillates                    63.4     66.9     67.6     63.8     67.6     66.9      67.6     63.8

  LPG
    Propane                                    1.1      1.1      1.2      1.1      1.2      1.1       1.2      1.1
    Isobutane                                  0.3      0.4      0.4      0.4      0.4      0.4       0.4      0.4
    Normal Butane                              2.1      2.2      2.2      2.1      2.2      2.2       2.2      2.1
                                             -----    -----    -----    -----    -----    -----     -----    -----
    SUBTOTAL - LPG                             3.5      3.7      3.8      3.6      3.8      3.7       3.8      3.6

  UNFINISHED
    Coker Propane Propylene Mix                2.1      2.2      2.2      2.1      2.2      2.2       2.2      2.1
    Coker Butane Butylene Mix                  1.5      1.6      1.6      1.5      1.6      1.6       1.6      1.5
    Penhex                                     9.1      9.5      9.7      9.1      9.7      9.5       9.7      9.1
    Virgin Diesel                              7.3      7.0      7.8      7.4      7.8      7.0       7.8      7.4
    Naphtha - Sour                            34.5     36.1     36.8     34.7     36.8     36.1      36.8     34.7
    Heavy Naphtha                              3.7      3.8      4.0      3.7      4.0      3.8       4.0      3.7
    ULS VGO                                   10.1     10.6     10.8     10.2     10.8     10.6      10.8     10.2
    VGO                                       43.6     45.8     46.5     43.9     46.5     45.8      46.5     43.9
                                             -----    -----    -----    -----    -----    -----     -----    -----
    SUBTOTAL - Unfinished                    112.0    116.5    119.4    112.5    119.4    116.5     119.4    112.5

  OTHER PRODUCTS
    Sulfur                                     1.2      1.3      1.3      1.2      1.3      1.3       1.3      1.2
    Coke                                      17.9     18.8     19.1     18.0     19.1     18.8      19.1     18.0
    Produced Fuel                              4.3      4.3      4.4      4.2      4.4      4.3       4.4      4.2
                                             -----    -----    -----    -----    -----    -----     -----    -----
    SUBTOTAL - Other Products                 23.5     24.4     24.9     23.4     24.9     24.4      24.9     23.5

  TOTAL PRODUCTS                             202.4    211.5    215.7    203.3    215.7    211.5     215.7    203.3

Chargestocks - Volume (bpd in thousands)
  CRUDE
    Arab Lt.                                  37.7     39.5     40.2     37.9     40.2     39.5      40.2     37.9
    Maya                                     150.9    157.8    160.9    151.7    160.9    157.8     160.9    151.7
                                             -----    -----    -----    -----    -----    -----     -----    -----
    SUBTOTAL - Crude                         188.6    197.3    201.1    189.6    201.1    197.3     201.1    189.6

  OTHER CHARGESTOCKS
    GFU Feed                                   1.5      1.6      1.6      1.5      1.6      1.6       1.6      1.5
    Hydrogen                                   3.4      3.5      3.6      3.4      3.6      3.5       3.6      3.4
                                             -----    -----    -----    -----    -----    -----     -----    -----
    SUBTOTAL - Other Chargestocks              4.9      5.1      5.2      4.9      5.2      5.1       5.2      4.9

  TOTAL CHARGESTOCKS                         193.5    202.4    206.3    194.5    206.3    202.4     206.3    194.5
</TABLE>

<PAGE>

                                  TABLE V-10
                        PORT ARTHUR COKER COMPANY L.P.
                                   BASE CASE
                                PRICE FORECAST

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

<TABLE>
<CAPTION>
                                       2001     2002     2003     2004     2005     2006     2007     2008
                                       ----     ----     ----     ----     ----     ----     ----     ----
<S>                                    <C>      <C>      <C>      <C>      <C>      <C>      <C>      <C>
Products - ($/bbl)
  DISTILLIATES
    LS Diesel                          18.94    20.69    21.66    22.39    22.85    23.09     23.35   23.60
    Jet Fuel                           19.45    21.16    22.12    22.84    23.30    23.55     23.80   24.07

  LPG
    Propane                            11.67    12.65    13.22    13.63    13.91    14.16     14.36   14.55
    Isobutane                          15.13    16.35    17.10    17.61    17.93    18.04     18.23   18.41
    Normal Butane                      12.45    13.57    14.27    14.73    15.02    15.12     15.28   15.44

  UNFINISHED
    Coker Propane Propylene Mix        13.94    15.28    16.39    16.88    17.22    17.48     17.71   17.91
    Coker Butane Butylene Mix          15.41    16.87    17.72    18.36    18.78    19.01     19.23   19.46
    Penhex                             14.36    15.60    16.31    16.84    17.18    17.34     17.53   17.73
    Virgin Diesel                      17.14    18.84    19.79    20.50    20.95    21.18     21.43   21.68
    Naphtha - Sour                     17.05    18.73    19.61    20.27    20.70    20.93     21.17   21.42
    Heavy Naphtha                      19.82    21.50    22.38    23.05    23.47    23.70     23.95   24.19
    ULS VGO                            17.73    19.43    19.93    20.53    20.97    21.20     21.43   21.67
    VGO                                15.57    17.22    17.69    18.24    18.66    18.88     19.10   19.33

  OTHER PRODUCTS
    Sulfur                              9.42     9.48     9.66     9.77     9.88     9.99     10.10   10.22
    Coke                               (0.17)    0.00     0.06     0.07     0.13     0.16      0.19    0.21
    Produced Fuel                      12.51    12.85    13.08    13.26    13.38    13.46     13.62   13.77

Chargestocks - ($/bbl)
  CRUDE
    Arab Lt.                           14.82    16.25    16.98    17.50    17.89    18.09     18.29   18.49
    Maya                               11.87    12.98    13.46    13.73    14.08    14.24     14.41   14.58

  OTHER CHARGESTOCKS
    GFU Feed                           17.13    18.82    19.76    20.46    20.91    21.14     21.38   21.62
    Hydrogen                           28.84    29.20    29.49    30.33    30.26    30.50     30.79   31.51
</TABLE>

                                       2
<PAGE>

                                  TABLE V-11
                        PORT ARTHUR COKER COMPANY L.P.
                                   BASE CASE
                      REVENUE AND FEEDSTOCK COST FORECAST

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

<TABLE>
<CAPTION>
                                                   2001      2002      2003      2004      2005      2006      2007      2008
                                                  ------    ------    ------    ------    ------    ------    ------    ------
<S>                                               <C>       <C>       <C>       <C>       <C>       <C>       <C>       <C>
Product Revenue (Dollars in Millions)
  DISTILLATES
   LS Diesel                                       264.6     306.5    322.6      315.2     340.4     342.1     347.7     332.3
   Jet Fuel                                        178.7     203.3    216.6      211.4     228.2     226.3     233.2     222.8
                                                  ------    ------   ------     ------    ------    ------    ------    ------
   SUBTOTAL - Distillates                          443.4     509.8    539.3      526.6     568.6     568.4     580.9     555.1

  LPG
   Propane                                           4.6       5.2      5.6        5.4       5.9       5.8       6.1       5.8
   Isobutane                                         1.9       2.2      2.3        2.3       2.4       2.4       2.5       2.4
   Normal Butane                                     9.5      10.8     11.7       11.4      12.3      12.1      12.5      11.9
                                                  ------    ------   ------     ------    ------    ------    ------    ------
   SUBTOTAL - LPG                                   16.1      18.2     19.6       19.1      20.6      20.3      21.0      20.1

  UNFINISHED
   Coker Propane Propylene Mix                      10.6      12.1     13.2       12.9      13.9      13.8      14.3      13.7
   Coker Butane Butylene Mix                         8.4       9.6     10.3       10.1      10.9      10.8      11.2      10.7
   Penhex                                           47.6      53.9     57.6       56.2      60.7      59.9      61.9      59.2
   Virgin Diesel                                    46.0      48.4     56.6       55.4      59.9      54.4      61.3      58.6
   Naphtha-Sour                                    214.9     246.8    263.4      257.3     278.0     275.8     284.3     271.8
   Heavy Naphtha                                    26.8      29.8     32.3       31.4      33.9      32.9      34.6      33.0
   ULS VGO                                          65.6      75.4     78.6       76.5      82.7      82.3      84.6      80.8
   VGO                                             248.1     287.7    300.3      292.7     316.9     315.4     324.4     310.2
                                                  ------    ------   ------     ------    ------    ------    ------    ------
   SUBTOTAL - Unfinished                           668.0     763.7    812.4      792.7     856.9     845.4     876.4     838.0

  OTHER PRODUCTS
   Sulfur                                            4.2       4.4      4.6        4.4       4.7       4.7       4.8       4.6
   Coke                                             (1.1)      0.0      0.4        0.5       0.9       1.1       1.3       1.4
   Produced Fuel                                    19.6      20.3     21.1       20.1      21.6      21.3      21.9      21.1
                                                  ------    ------   ------     ------    ------    ------    ------    ------
   SUBTOTAL - Other Products                        22.8      24.8     26.1       25.0      27.2      27.0      28.1      27.2

  TOTAL PRODUCT REVENUE                           1150.2    1316.5   1397.4     1363.4    1473.3    1461.2    1506.4    1440.4

  CRUDE
   Arab Lt.                                        204.2     234.0    249.3      242.8     262.7     260.5     268.5     256.7
   Maya - Market                                   654.2     747.6    790.3      762.3     827.1     820.5     846.3     809.3
                                                  ------    ------   ------     ------    ------    ------    ------    ------
   SUBTOTAL - Crude                                858.4     981.6   1039.6     1005.2    1089.8    1081.0    1114.8    1066.0

Chargestock Cost (Dollars in Millions)
 OTHER CHARGESTOCK
   GFU Feed                                          9.5      11.1     11.7       11.4      12.3      12.5      12.6      12.1
   Hudrogen                                         35.3      37.4     38.6       37.5      39.6      39.1      40.3      39.0
                                                  ------    ------   ------     ------    ------    ------    ------    ------
   SUBTOTAL - Other Chargestocks                    44.8      48.5     50.2       48.9      51.9      51.6      52.9      51.0

 TOTAL CHARGESTOCK COST                            903.2    1030.1   1089.8     1054.1    1141.7    1132.6    1167.7    1117.0
</TABLE>

                                       3

<PAGE>

                                  TABLE V-12
                        PORT ARTHUR COKER COMPANY L.P.
                                   BASE CASE
                        CASH FLOW AND DEBT AMORTIZATION

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------------------------------

(Dollars in Millions)
                                                       2001      2002     2003      2004      2005      2006     2007      2008
                                                       ----      ----     ----      ----      ----      ----     ----      ----
<S>                                                  <C>       <C>       <C>       <C>       <C>       <C>      <C>       <C>
Total Product Revenue                                1,150.2   1,316.5   1,397.4   1,363.4   1,473.3   1,462.2  1,506.4   1,440.4
Total Chargestock Cost                                 903.2   1,030.1   1,089.8   1,054.1   1,141.7   1,132.6  1,167.7   1,117.0
                                                     -------   -------   -------   -------   -------   -------  -------   -------
  Refinery Gross Margin                                247.0     286.4     307.5     309.3     331.6     328.6    338.7     323.4

PMI Contract Coker Gross Margin Guarantee               43.8      19.0      (2.7)    (22.6)    (28.0)    (23.9)
                                                     -------   -------   -------   -------   -------   -------  -------   -------
Total Gross Margin                                     290.8     305.4     304.8     286.7     303.6     304.6    338.7     323.4

Variable Operating Expenses                             26.5      27.9      28.5      28.0      29.1      28.9     29.6      29.0
Fixed Operating Expenses                                34.3      34.4      35.0      35.8      37.5      39.3     41.5      42.8
Lease Fees                                              31.6      32.2      32.8      33.6      34.2      34.8     35.5      36.4
Operating Fees                                          58.5      61.4      63.2      59.4      62.3      62.6     64.0      62.9
Processing Fees                                        (69.7)    (72.0)    (73.4)    (74.1)    (76.1)    (77.4)   (78.9)    (79.7)
G&A Expense                                              0.7       0.8       0.8       0.8       0.8       0.8      0.8       0.9
                                                     -------   -------   -------   -------   -------   -------  -------   -------
  Total Expenses                                        81.9      84.7      86.8      83.5      87.7      89.1     92.6      92.2

  Operating Cash Flow                                  208.8     220.7     218.0     203.2     215.9     215.5    246.1     231.2

Other Cash Items
Interest Income                                          1.9       2.7       3.1       3.1       2.1       2.3      3.6       5.3
Cash Taxes                                                       (18.3)    (32.1)    (27.1)    (48.5)    (53.6)   (68.1)    (50.6)
Mandatory Capex                                         (3.0)     (2.3)     (2.4)     (2.4)     (3.8)     (3.9)    (4.0)     (4.1)
Turnaround Expense                                      (7.5)     (7.5)     (7.5)     (7.5)     (9.9)     (9.9)    (9.9)     (9.9)
Catalyst Adjustment                                      2.7      (2.1)      2.2      (2.9)      2.9      (2.9)     3.0      (3.1)
Other                                                    1.6       5.7       5.4       5.0       1.4      (6.4)    (0.7)     (0.7)
                                                     -------   -------   -------   -------   -------   -------   -------   ------
   Total Other Cash Items                               (4.4)    (21.9)    (31.3)    (31.9)    (55.8)    (74.4)   (76.0)    (63.0)

Cash Flow Available For Debt Service                   204.4     198.9     186.7     171.3     160.0     141.2     170.1    168.2

Debt Service (1)
----------------
Interest / Financing Fees                               70.4      57.1      44.4      33.3      28.2      22.4      16.8     11.1
Principal                                               12.4      44.5      29.0      30.6      46.4      46.4      40.3     61.7
                                                     -------   -------   -------   -------   -------   -------   -------  -------
  Total Debt Service                                    82.8     101.6      73.4      63.9      74.6      68.8      57.1     72.8

DSCR                                                     2.5       2.0       2.5       2.7       2.1       2.1       3.0      2.3
Average                                                  2.4
Minimum                                                  2.0

Debt Amortization Schedule
--------------------------
Capital Markets
Interest Payment                                        31.9      31.6      30.1      27.2      22.9      17.1      11.5      5.8
Principal Payment                                                  8.7      20.9      30.6      46.4      46.4      40.3     61.7

Bank Debt
Interest Payment                                        31.6      20.1       9.0       0.8
Principal Payment - Scheduled                           12.4      35.8       8.1
Principal Payment - Sweep                               95.8      73.0      85.0      15.0
</TABLE>

(1) Annual debt service for a given year includes July 15 debt service for
    subject year and January 15 debt service for following year.

                                       4
<PAGE>

                                  TABLE V-13
                        PORT ARTHUR COKER COMPANY L.P.
                                   BASE CASE
                               SOURCES AND USES
--------------------------------------------------------------------------------

<TABLE>
<CAPTION>
(Dollars in Millions)                                                            Project Cost

                                                                Total PACC        Total Clark      Total Project
                                                              -----------------------------------------------------
<S>                                                           <C>                <C>               <C>
Uses of Funds
------------------------------------------------

EPC costs                                                           543.9               92.0             635.9
Project Contingency                                                  28.0                                 28.0
Taxes and Import Duties                                               5.0                                  5.0
Project Team Cost                                                                       26.0              26.0
Startup Cost (includes initial Cat & Chem)                           14.6                                 14.6
                                                                   ------             ------           -------
 Total Cash Construction Cost                                       591.5              118.0             709.5

Transfer of Value                                                     2.2               (2.2)
Interesting during construction                                      89.7                                 89.7
Interest Income                                                      (0.9)                                (0.9)
Legal / Consulting / Other Fees                                      11.4                2.0              13.4
Financing expenses                                                   21.1                                 21.1
                                                                   ------             ------           -------
Total Uses                                                          715.0              117.8             832.8

Sources of Funds
------------------------------------------------

Bank Debt                                                           325.0                                325.0
Capital Markets                                                     255.0                                255.0
Cash Equity                                                         135.0              117.8             252.8
                                                                   ------             ------           -------
Total Sources                                                       715.0              117.8             832.8
</TABLE>

                                       5

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