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                                                                    Exhibit 10.6

                              AMENDED AND RESTATED
                              EMPLOYMENT AGREEMENT

          AMENDED AND RESTATED EMPLOYMENT AGREEMENT (the "Agreement") effective
June 1, 2002 by and between Premcor Inc. (the "Company") and Joseph D. Watson
(the "Executive").

          WHEREAS, Executive became the Senior Vice President and Chief
Administrative Officer of the Company on March 1, 2002, and on that date
Executive and the Company entered into an Employment Agreement; and

          WHEREAS, Executive and the Company desire to amend and restate that
agreement in its entirety.

          1. Term of Employment. Subject to the provisions of Section 8,
Executive shall be employed by the Company for a period commencing on June 1,
2002 ("Start Date") and ending on June 1, 2004 (the "Employment Term") on the
terms and subject to the conditions set forth in this Agreement. However,
commencing on June 1, 2004 and on each June 1 thereafter (each an "Extension
Date"), the Employment Term shall be automatically extended for an additional
one-year period, unless the Company or Executive provides the other party hereto
not less than 60 days prior written notice before the next Extension Date that
the Employment Term shall not be so extended.

          2. Position.

               a.   During the Employment Term, Executive shall serve as the
Senior Vice President and Chief Administrative Officer of the Company. In such
position, Executive shall have such duties and authority as shall be determined
from time to time by the Chief Executive Officer and/or Board of Directors of
the Company (the "Board").

               b.   During the Employment Term, Executive shall devote
Executive's full business time and best efforts to the performance of
Executive's duties hereunder and shall not engage in any other business,
profession or occupation for compensation or otherwise which would conflict or
interfere with the rendition of such services either directly or indirectly,
without the prior written consent of the Board; provided that nothing herein
shall preclude Executive (i) from continuing to serve on any board of directors
or trustees of any business corporation or any charitable organization and (ii)
subject to the prior written approval of the Board, which approval shall not be
unreasonably withheld, from accepting appointment to any 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 materially conflict
or interfere with the performance of Executive's duties hereunder or conflict
with Section 9.

          3. Base Salary. During the Employment Term, the Company shall pay
Executive a base salary at the annual rate of $200,000, 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. Executive's
annual rate of base salary, as in effect from time to time, is hereinafter
referred to as the "Base Salary."

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          4. Annual Bonus. With respect to each fiscal year of the Company
ending during the Employment Term, Executive shall be eligible to earn an annual
bonus award (an "Annual Bonus") if net earnings per share to common shareholders
of the Company, calculated on a fully diluted basis and according to GAAP, as
determined by the Company's outside auditors, excluding the after-tax impact of
any extraordinary or special items that the Board determines in good faith are
not appropriately includable in the Annual Bonus calculation because such items
do not accurately reflect the operating performance of the Company, such as
inventory write ups and write downs, LIFO adjustments, asset purchase or
sale-related gains or losses and acquisition-related write downs ("Adjusted
EPS"), is at least equal to $2.50. Upon achievement of an Adjusted EPS of $2.50,
the Annual Bonus shall equal fifty percent (50%) of Executive's Base Salary (the
"Base Bonus"). For each $0.01 increase in the applicable fiscal year's Adjusted
EPS above $2.50, the Annual Bonus shall be increased by an amount equal to one
percent of Executive's Base Salary, provided that in no event shall the Annual
Bonus be greater than three times Executive's Base Salary. The Annual Bonus
shall be paid to Executive within fifteen business days after the outside
auditors approve the Company's year-end earnings release. Executive's Annual
Bonus for 2002 shall be calculated based on earnings from January 1, 2002 and
the resulting amount multiplied by 10/12ths, to arrive at the amount due for the
ten months of 2002, so long as Executive is employed hereunder as of December
31, 2002. Annual Bonuses for subsequent full years during which Executive is
employed hereunder will reflect the full year (January 1 through December 31).

          5. Equity Arrangements. During the month of January in each of the
years 2003 and 2004, Executive shall receive a grant of options to purchase not
less than 25,000 shares of Company common stock at an exercise price per share
equal to Fair Market Value (as defined in the Plan) on the date of grant (the
"Annual Options"). Subject to Executive's continued employment with the Company,
such Annual Options will vest in equal installments on each of the first three
anniversaries of the date of grant, and will become fully vested upon the
occurrence of a Change in Control of the Company. Other terms and conditions of
the Annual Options shall be as set forth herein, in the Plan and an option
agreement between the Company and Executive. If the Company should, prior to any
Annual Option grant, be involved in any merger, reorganization, stock split or
spinoff or other similar event, the number of shares subject to the Annual
Options yet to be granted, as provided above, shall be adjusted on a pro rata
basis.

          6. Employee Benefits. During the Employment Term, Executive shall be
entitled to participate in the Company's employee benefit plans (which term does
not include bonus or incentive compensation plans), other than any severance pay
plan, as in effect from time to time (collectively "Employee Benefits"), on the
same basis as those benefits are generally made available to other senior
executives of the Company. Executive shall also be a participant in the Premcor
Senior Executive Retirement Plan as approved by the Board of Directors of the
Company on April 2, 2002.

          7. Business Expenses. During the Employment Term, reasonable business
expenses incurred by Executive in the performance of Executive's duties
hereunder shall be reimbursed by the Company following presentation by Executive
of proof of such expenses, as and when reasonably required by the Company.

          8. Termination. The Employment Term and Executive's employment
hereunder may be terminated by the Company at any time and for any reason or by
Executive for Good

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Reason. Notwithstanding any other provision of this Agreement (other than
Section 13(h)), the provisions of this Section 8 shall exclusively govern
Executive's rights upon termination of employment with the Company and its
affiliates.

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

            (i)   If Executive's employment is terminated by the Company for
Cause, or if Executive resigns 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 fiscal year (including, if
     applicable, 2002);

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

               (D) such Employee Benefits, if any, as to which Executive may be
     entitled under the employee benefit plans of the Company (the amounts
     described in clauses (A) through (D) hereof being referred to as the
     "Accrued Rights"); and

               (E) any vested benefits as provided pursuant to the Premcor
     Senior Executive Retirement Plan, accrued in respect to any prior fiscal
     year.

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

            (ii)  For purposes of this Agreement, "Cause" shall mean (A)
Executive's continued failure substantially to 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 20 days following written notice by the
Company to Executive of such failure, (B) Executive's conviction of, or plea of
nolo contendere to a crime constituting (x) a felony under the laws of the
United States or any state thereof or (y) a misdemeanor involving moral
turpitude, (C) Executive's willful malfeasance or willful misconduct in
connection with Executive's duties hereunder or any act or omission which is
injurious to the financial condition or business reputation of the Company or
any of its subsidiaries or affiliates, other than an act or omission that was
committed or omitted by Executive in the good faith belief that it was in the
best interest of the Company or (D) Executive's breach of the provisions of
Sections 9 or 10 of this Agreement.

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               b.   Disability or Death.

            (i)   The Employment Term and Executive's employment hereunder shall
terminate upon Executive's death and may be terminated by the Company if
Executive becomes physically or mentally incapacitated and is therefore unable
for a period of six (6) consecutive months or for an aggregate of nine (9)
months in any twenty-four (24) consecutive month period 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;

               (B) a pro rata portion of any Annual Bonus, if any, that
     Executive would have been entitled to receive pursuant to Section 4 hereof
     in such year based upon the percentage of the fiscal year that shall have
     elapsed through the date of Executive's termination of employment, payable
     when such Annual Bonus would have otherwise been payable had Executive's
     employment not terminated; and

               (C) any vested benefits as provided in the Premcor Senior
     Executive Retirement Plan, accrued to the date of termination of
     employment.

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

               c.   By the Company Without Cause or Resignation by Executive for
Good Reason.

            (i)   If Executive's employment is terminated by the Company without
Cause (other than by reason of death or Disability) or if Executive resigns for
Good Reason, Executive shall be entitled to receive:

               (A) the Accrued Rights;

               (B) subject to Executive's continued compliance with the
     provisions of Sections 9 and 10, payment, within 60 days of the date of
     termination of Executive's employment, of a lump sum equal to three times
     the sum of Executive's Base Salary and Base Bonus; and

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               (C) the benefits as provided in the Premcor Senior Executive
     Retirement Plan, whether or not previously vested.

          Following Executive's termination of employment by the Company without
Cause (other than by reason of Executive's death or Disability) or by
Executive's resignation for Good Reason, except as set forth in this Section
8(c)(i), and the Plan and any applicable option agreement, Executive shall have
no further rights to any compensation or any other benefits under this
Agreement.

            (ii)  For purposes of this Agreement, "Good Reason" shall mean,
without Executive's consent, (A) the failure of the Company to pay or cause to
be paid Executive's Base Salary or Annual Bonus, when due hereunder, (B) any
substantial and sustained diminution in Executive's authority or
responsibilities from those described in Section 2 hereof or (C) relocation of
Executive's principal place of business by more than 30 miles, provided that
relocation to St. Louis, MO or Greenwich, CT shall not constitute Good Reason;
provided that the events described in clauses (A), (B) and (C) of this Section
8(c)(ii) shall constitute Good Reason only if the Company fails to cure such
event within 20 days after receipt from Executive of written notice of the event
which constitutes Good Reason; provided, further, that "Good Reason" shall cease
to exist for an event on the 90th day following the later of its occurrence or
Executive's knowledge thereof, unless Executive has given the Company written
notice thereof prior to such date.

               d.   Expiration of Employment Term.

            (i)   Election Not to Extend the Employment Term. In the event
either party 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. If Executive provides the Company
notice of non-extension of the Employment Term pursuant to Section 1, Executive
shall be entitled to receive the Accrued Rights. If the Company provides
Executive notice of non-extension of the Employment Term pursuant to Section 1,
Executive shall be entitled to receive the benefits provided in Sections
8(c)(i)(A)-(C), above.

          Following such termination of Executive's employment hereunder as a
result either party's election not to extend the Employment Term, except as set
forth in this Section 8(d)(i), Executive shall have no further rights to any
compensation or any other benefits under this Agreement.

               e.   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 13(g) 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.

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               f.   Board/Committee Resignation. Upon termination of Executive's
employment for any reason, Executive agrees to resign, as of the date of such
termination and to the extent applicable, from the Board (and any committees
thereof) and the Board of Directors (and any committees thereof) of any of the
Company's affiliates.

          9. Non-Solicitation; Non-Competition.

               a.   Executive acknowledges and recognizes the highly competitive
nature of the businesses of the Company and its affiliates and accordingly
agrees as follows:

          (1)       While Executive is employed by the Company and for six
months following the date Executive ceases to be employed by the Company (the
"Restricted Period"), Executive shall not, whether on Executive's own behalf or
on behalf of or in conjunction with any person, company, business entity or
other organization whatsoever, directly or indirectly

              (i)   solicit, or assist in soliciting, in competition with the
                    Company, the potential acquisition of refining assets in
                    the United States;

              (ii)  solicit or encourage any employee of the Company or its
                    affiliates to leave the employment of the Company or its
                    affiliates;

              (iii) hire any such person who was employed by the Company or its
                    affiliates as of the date of Executive's termination of
                    employment with the Company or whose employment with the
                    Company terminated within six months prior to the date of
                    such hire (other than any such person whose employment was
                    terminated by the Company without cause); or

              (iv)  solicit or encourage to cease to work with the Company or
                    its affiliates any consultant then under contract with the
                    Company or its affiliates.

          (2)       While Executive is employed by the Company and, following
termination of employment by the Company for Cause or by Executive without Good
Reason, for the remainder of the Employment Term (without regard to Executive's
termination of employment), Executive shall not directly or indirectly:

              (i)   engage in the business of petroleum refining or oil product
                    wholesaling in the United States

              (ii)  engage in any other business in which the Company or its
                    affiliates is engaged at the time of the termination of
                    Executive's employment, provided such other business is
                    contributing more than 10% of the Company's consolidated
                    annual revenues or net income at the time of the
                    termination of Executive's employment (any of the
                    businesses described in the preceding subparagraph (i) and
                    this subparagraph (ii) being referred to as a "Competitive
                    Business");

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              (iii) enter the employ of, or render any services to, any entity
                    (or any division, affiliate, business unit or segment of
                    any entity) which engages in a Competitive Business;
                    provided that, notwithstanding the foregoing, it shall not
                    be a breach of Section 9(a)(2) for Executive to provide
                    services to any division, affiliate, business unit or
                    segment of any entity so long as (x) such division,
                    affiliate, business unit or segment does not itself engage
                    in a Competitive Business and (y) Executive does not,
                    directly or indirectly, provide services or advice to any
                    division, affiliate, business unit or segment of the entity
                    that does engage in a Competitive Business;

              (iv)  acquire a financial interest in (other than a passive
                    investment acquired through a hedge fund or similar
                    vehicle), or otherwise become actively involved with, any
                    Competitive Business, directly or indirectly, as an
                    individual, partner, shareholder, officer, director,
                    principal, agent, trustee or consultant; or

              (v)   interfere with, or attempt to interfere with, business
                    relationships (whether formed before, on or after the date
                    of this Agreement) between the Company or any of its
                    affiliates and their customers, clients or suppliers in
                    connection with or on behalf of a Competitive Business.

          (3)       Notwithstanding anything to the contrary in this Agreement,
Executive may, directly or indirectly own, solely as an investment, securities
of any person engaged in the business of the Company or its affiliates which are
publicly traded on a national or regional stock exchange or on the
over-the-counter market if Executive (i) is not a controlling person of, or a
member of a group which controls, such person and (ii) does not, directly or
indirectly, own 5% or more of any class of securities of such person.

               b.   It is expressly understood and agreed that although
Executive and the Company consider the restrictions contained in this Section 9
to be reasonable, if a final judicial determination is made by a court of
competent jurisdiction that the time or territory or any other restriction
contained in this Agreement is an unenforceable restriction against Executive,
the provisions of this Agreement shall not be rendered void but shall be deemed
amended to apply as to such maximum time and territory and to such maximum
extent as such court may judicially determine or indicate to be enforceable.
Alternatively, if any court of competent jurisdiction finds that any restriction
contained in this Agreement is unenforceable, and such restriction cannot be
amended so as to make it enforceable, such finding shall not affect the
enforceability of any of the other restrictions contained herein.

          10. Confidentiality. Executive agrees to hold all Company information
confidential ("Confidential Information") and shall not at any time disclose,
retain, or use such Confidential Information for Executive's own benefit or the
benefit of any other person, without the written authorization of the Board;
provided that the foregoing shall not apply to the extent that information is
required to be disclosed by law. Executive agrees that upon termination of
Executive's employment with the Company for any reason, he shall return to the
Company

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immediately all Confidential Information and all copies thereof or therefrom, in
any way relating to the business of the Company.

          11. 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 or Section 10 would be inadequate and the Company would
suffer irreparable damages as a result of such breach or threatened breach. 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.

          12. Gross-Up Payment.

               a.   If it shall be determined that any amount, right or benefit
paid, distributed or treated as paid or distributed by the Company or any of its
affiliates to or for Executive's benefit (other than any amounts payable
pursuant to this Section 12) (a "Payment") would be subject to the excise tax
imposed by Section 4999 of the Internal Revenue Code of 1986 (the "Code"), or
any interest or penalties are incurred by Executive with respect to such excise
tax (such excise tax, together with any such interest and penalties,
collectively, the "Excise Tax"), then Executive shall be entitled to receive an
additional payment (a "Gross-Up Payment") in an amount equal to the amount
necessary such that after payment by Executive of all federal, state and local
taxes (including any interest or penalties imposed with respect to such taxes),
including, without limitation, any income taxes (and any interest and penalties
imposed with respect thereto) and Excise Tax imposed upon the Gross-Up Payment,
Executive retains an amount of the Gross-Up Payment equal to the Excise Tax
imposed upon the Payments.

               b.   All determinations required to be made under this
Section 12, including whether and when a Gross-Up Payment is required, the
amount of such Gross-Up Payment and the assumptions to be utilized in arriving
at such determination, shall be made by the Company's independent auditors (the
"Auditor"). The Auditor shall provide detailed supporting calculations to both
the Company and Executive within 15 business days of the receipt of notice from
Executive or the Company that there has been a Payment, or such earlier time as
is requested by the Company. All fees and expenses of the Auditor shall be paid
by the Company. Any Gross-Up Payment, as determined pursuant to this Section 12,
shall be paid by the Company to Executive (or to the Internal Revenue Service or
other applicable taxing authority on Executive's behalf) within 5 days of the
receipt of the Auditor's determination. All determinations made by the Auditor
shall be binding upon the Company and Executive; provided that following any
payment of a Gross-Up Payment to Executive (or to the Internal Revenue Service
or other applicable taxing authority on Executive's behalf), the Company may
require Executive to sue for a refund of all or any portion of the Excise Taxes
paid on Executive's behalf, in which event the provisions of Section 12(c) below
shall apply. As a result of uncertainty regarding the application of Section
4999 of the Code hereunder, it is possible that the Internal Revenue Service may
assert that Excise Taxes are due that were not included in the Auditor's
calculation of the Gross-Up Payments (an Underpayment"). In the event that the
Company exhausts its remedies pursuant to this Section 12 and Executive
thereafter is required to make a payment of any Excise Tax, the Auditor shall
determine the amount of the

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Underpayment that has occurred and any additional Gross-Up Payments that are due
as a result thereof shall be promptly paid by the Company to Executive (or to
the Internal Revenue Service or other applicable taxing authority on Executive's
behalf).

               c.   Executive shall notify the Company in writing of any claim
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 10 business days after Executive receives written notification of such
claim and shall apprise the Company of the nature of such claim and the date on
which such claim is requested to be paid. Executive shall not pay such claim
prior to the expiration of the 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 due). If the Company
notifies Executive in writing prior to the expiration of such period that it
desires to contest such claim, Executive shall: (i) give the Company all
information reasonably requested by the Company relating to such claim; (ii)
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 and ceasing all efforts to contest such
claim; (iii) cooperate with the Company in good faith in order to effectively
contest such claim; and (iv) permit the Company to participate in any proceeding
relating to such claim; provided, however, that the Company shall bear and pay
directly all reasonable 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, from any Excise Tax or income tax
(including interest and penalties with respect thereto) imposed as a result of
such representation and payment of costs and expense. Without limiting the
foregoing provisions of this Section 12, the Company shall control all
proceedings taken in connection with such contest 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 Executive to pay the tax claimed and sue for a refund
or contest the claim in any permissible manner, and 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 and direct; provided, however that if 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) imposed with respect to such advance or with respect to any imputed
income with respect to such advance; and further provided that any extension of
the statute of limitations relating to payment of taxes for Executive's taxable
year with respect to which such contested amount is claimed to be due is limited
solely to such contested amount. Furthermore, 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.

               d.   If, after the Executive's receipt of an amount advanced by
the Company pursuant to this Section 12, the Executive becomes entitled to
receive any refund with respect to such claim, the Executive shall 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 Executive's
receipt of an amount advanced by the Company pursuant to this Section 12,

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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 30 days after the Company's receipt of notice of 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.

          13. Miscellaneous.

               a.   Governing Law; Jurisdiction. This Agreement shall be
governed by and construed in accordance with the laws of the State of New York,
without regard to conflicts of laws principles thereof. Any suit, action or
proceeding related to this Agreement, or any judgment entered by any court
related to this Agreement, may be brought only in any court of competent
jurisdiction in the State of New York, and the parties hereby submit to the
exclusive jurisdiction of such courts. The parties (and any affiliates of the
Company or beneficiary or permitted transferee of Executive) irrevocably waive
any objections which they may now or hereafter have to the laying of venue of
any suit, action or proceeding brought in any court of competent jurisdiction in
the State of New York, and hereby irrevocably waive any claim that any such
action, suit or proceeding has been brought in an inconvenient forum.

               b.   Entire Agreement; Amendments. This Agreement contains the
entire understanding of the parties with respect to the matters herein
(including, without limitation, Executive's compensation, benefits and
severance). 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.

               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.

               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, with Executive's
consent, such consent not to be unreasonably withheld, to a person or entity
that is a successor in interest to substantially all of the business operations
of the Company. Upon such assignment, the rights and obligations of the Company
hereunder shall become the rights and obligations of such affiliate or successor
person or entity.

               f.   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 of the
Executive.

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                                                                              11

               g.   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 by hand or overnight courier or
five days after it has been 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:

          Premcor Inc.
          8182 Maryland Avenue
          Suite 600
          St. Louis, MO  63105
          Attention:  General Counsel

          With a copy to:

          The Blackstone Group, L.P.
          345 Park Avenue
          New York, NY  10154
          Attention:  Robert L. Friedman

          If to Executive:

          Joseph Watson
          8924 East Charter Oak Drive
          Scottsdale, AZ  85260

               h.   Release. As a condition of receipt of the benefits described
in Section 8, Executive will be required to enter into a full and complete
release of the Company from any and all claims which Executive may then have for
whatever reason or cause in connection with Executive's employment and the
termination thereof (including, without limitation, any rights under an
employment agreement which may then be in effect), other than those obligations
specifically set out in this Agreement, the Plan, indemnification provisions in
the Company's by-laws and obligations of the Company to the extent that the
documents providing for such obligations specifically provide that the
obligations are in addition to obligations under this Agreement.

               i.   Disputes. Any dispute with regard to the enforcement of this
Agreement or any matter relating to the employment of Executive by the Company
including but not limited to disputes relating to claims of employment
discrimination, alleged torts or any violation of law other than the seeking of
equitable relief in accordance with applicable law under Section 11 hereof,
shall be exclusively resolved by a single experienced arbitrator licensed to
practice law in New York, selected in accordance with the American Arbitration
Association rules and procedures, at an arbitration to be conducted in New York
City pursuant to the National Rules for the Resolution of Employment Disputes
rules of the American Arbitration

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                                                                              12

Association ("AAA") with the arbitrator applying the substantive law of the
State of New York as provided for under Section 13(a) hereof. The AAA shall
provide the parties hereto with lists for the selection of arbitrators composed
entirely of arbitrators who are members of the National Academy of Arbitrators
and who have prior experience in the arbitration of disputes between employers
and senior executives. The determination of the arbitrator shall be final and
binding on the parties hereto and judgment therein may be entered in any court
of competent jurisdiction in accordance with Section 13(a). Each party shall pay
its own attorneys fees and disbursements and other costs of the arbitration.

               j.   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 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.

               k.   Cooperation. Executive shall provide his reasonable
cooperation in connection with any action or proceeding (or any appeal from any
action or proceeding) that relates to events occurring during Executive's
employment hereunder. The Company shall provide Executive with a reasonable
stipend and shall reimburse Executive for reasonable expenses incurred as a
result of Executive's cooperation with the Company. This provision shall survive
any termination of this Agreement.

               l.   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.

               m.   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.

               n.   Shareholder Approval. This Agreement shall be subject to,
and shall only be effective following, the approval of the Company's
shareholders as of the date hereof who owned, as of the date hereof, more than
75% of the voting power of all outstanding stock of the Company, determined and
obtained in a manner consistent with the methodology described in proposed
Treasury Regulation Section 1.280G-1, or any successor thereto.

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                                                                              13

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

          PREMCOR INC.


        /s/ Thomas D. O'Malley                       /s/ Joseph D. Watson
--------------------------------------------     ------------------------------
By:     THOMAS D. O'MALLEY                           JOSEPH D. WATSON
Title:  Chairman and Chief Executive Officer