EXHIBIT 10.6
                           UNOCAL EMPLOYMENT AGREEMENT



     This employment  agreement (the  "Agreement") is made effective as of March
27,  2000  by and  between  Unocal  Corporation,  a  Delaware  corporation  (the
"Company") and Charles R.  Williamson,  Group Vice  President,  Asia  Operations
("Employee").

     In  consideration  of the mutual  promises and agreements set forth herein,
the Company and Employee agree as follows:

1. Term.

     1.1 The term of this  Agreement  (the "Term")  shall  commence on March 27,
2000 and shall be for three years,  subject to earlier termination in accordance
with the  provisions  of Section 4  hereinbelow.  If the  Agreement has not been
subject to early  termination  in  accordance  with the  provisions of Section 4
hereinbelow,  beginning on March  27,2000 and on each day  thereafter,  the Term
shall  automatically  be  extended  for an  additional  day unless  the  Company
notifies  Employee in writing that it does not wish to further  extend the Term.
Notwithstanding  the  foregoing,  this  Agreement  shall end  automatically  and
without  additional  notice  on the  date of the  Company's  Annual  Meeting  of
Shareholders  that  next  follows  the  date of  Employee's  sixty-fifth  (65th)
birthday.

2. Position and Title.

     2.1 The Company on behalf of itself and its affiliates and subsidiaries
hereby  employs  Employee as  Executive  Vice  President,  International  Energy
Operations, and Employee hereby accepts such employment.

     2.2 Employee shall devote  substantially  all of his efforts on a full time
basis to the  business  and  affairs of the  Company and shall not engage in any
business  or perform  any  services in any  capacity  whatsoever  adverse to the
interests of the Company.

     2.3 Employee shall at all times faithfully, industriously, and to the
best of his ability,  experience,  and talents, perform all of the duties of his
position.

3. Compensation.

     3.1 As of the date of this  Agreement,  Employee's  annual  base  salary is
$400,008.  Employee's base salary and performance shall be reviewed periodically
at intervals approved by the Management  Development and Compensation  Committee
of the Board of Directors of the Company (the "Committee"),  and Employee's base
salary  may be  increased  from  time to  time  based  on  merit  or such  other
consideration as the Committee may deem appropriate.

     3.2 During the Term,  Employee  shall  participate  in all of the Company's
incentive  plans,  benefit  plans and  perquisites,  and in any new or successor
incentive plans,  benefit plans and perquisites,  that are generally provided to
executives of the Company with a level of responsibility  and stature comparable
to  Employee.   Performance  goals,  award  opportunity,   benefit  levels,  and
administrative guidelines for such plans shall be subject to review and approval
by the Committee.

4. Termination of Employment.

     4.1 During the Term, the Company may terminate Employee's employment herein
at any time for Cause or as a result of a  material  breach by  Employee  of his
obligations  under this Agreement,  provided however that, except in the case of
conviction of a felony,  the Company  shall provide  Employee with not less than
sixty (60) days prior written notice describing the behavior or conduct which is
alleged by the Company to constitute  Cause,

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and  Employee  shall be provided  with  reasonable  opportunity  to correct such
behavior or conduct  within the notice period.  For purposes of this  Agreement,
Cause shall be defined as any or all of the following:

     (1)  Conduct or action by Employee  which,  in the opinion of a majority of
          the Board of Directors, is materially harmful to the Company;

     (2)  Willful failure by Employee to follow an order of the Board, except in
          such case where the  Employee  believes  in good faith that  following
          such order would be  materially  detrimental  to the  interests of the
          Company;

     (3)  Employee's conviction of a felony.

     4.2 In the event that  Employee's  employment  is terminated by the Company
for any reason other than those set forth in Paragraph 4.1 hereinabove,  or, (a)
Employee's  annual base salary is reduced  below the amount  stated in Paragraph
3.1 hereinabove  (unless such reduction is part of an across the board reduction
affecting  all Company  executives  with a comparable  level of  responsibility,
title or stature),  or (b) Employee is removed from or denied  participation  in
incentive plans, benefit plans, or perquisites generally provided by the Company
to other executives with a comparable level of responsibility, title or stature,
or (c) Employee's  target  incentive  opportunity,  benefits or perquisites  are
reduced  relative to other executives with comparable  responsibility,  title or
stature, or (d) Employee is assigned duties or obligations inconsistent with his
position with the Company or (e) There is a significant change in the nature and
scope of Employee's  authority or his overall  working  environment,  such event
shall be considered a Termination Without Cause.

     4.3 In the event of Employee's Termination Without Cause at any time during
the Term of this Agreement, then:

     (1)  The Company  shall pay  Employee a lump-sum  severance  amount  within
          thirty (30) days  following  Termination  Without Cause equal to three
          (3) times  the sum of (a) the  higher of the  Employee's  annual  base
          salary at the time of  Termination  Without  Cause or the annual  base
          salary stated in Paragraph 3.1 hereinabove,  and (b) the annual target
          Bonus  applicable to Employee as of the beginning of the calendar year
          in which such Termination Without Cause occurs,  reduced by the amount
          of any Unocal Employee  Redeployment Program and/or Unocal Termination
          Allowance benefits payable to Employee.

     (2)  The Company  shall  provide for Employee to receive  medical,  dental,
          life, and disability  insurance coverage for three (3) years following
          Termination  Without  Cause  at  levels  and a net  cost  to  Employee
          comparable  to  that  provided  to  Employee   immediately   prior  to
          Employee's Termination Without Cause.

     (3)  The Company shall pay Employee an additional lump-sum severance amount
          within thirty (30) days following Employee's Termination Without Cause
          equal to three (3) times the base salary used to  determine  the lump-
          sum severance benefit in paragraph 4.3(1)  hereinabove,  multiplied by
          6% (.06).

     4.4 In the event that  during the Term of this  Agreement  Employee  should
voluntarily  resign  from the  Company,  should  terminate  employment  with the
Company due to death,  permanent disability or incapacitation,  or is terminated
by the Company for Cause or for a material breach by Employee of his obligations
under  this  Agreement,  then  Employee  shall  not  be  entitled  to any of the
termination benefits provided for in Paragraph 4.3 hereinabove,  and the Term of
the Agreement shall immediately end.

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     4.5 Employee  shall not be obligated to seek other  employment  or take any
other action by way of mitigation of the amounts  payable to Employee  under any
provisions of this Agreement.

5. Change of Control.

     5.1 In the event of a Change of Control of the  Company at any time  during
the Term of this Agreement, then:

     (1)  In the event of Employee's  Termination  Without Cause within a period
          of twenty-four  (24) months following the date of a Change of Control,
          Employee shall be entitled to the  termination  benefits  described in
          Paragraph 4.3 hereinabove; provided that the lump-sum severance amount
          paid to Employee  under this  Paragraph  5.1(1),  which is  calculated
          based  on  Paragraphs  4.3(1)  and  4.3(3)  hereinabove,  shall be (a)
          reduced to equal the present  value,  determined  in  accordance  with
          Section  280G(d)(4) of the Internal  Revenue Code (the "IRC"),  of the
          lump-sum  severance  amount  which would  otherwise  be payable  under
          Paragraphs 4.3(1) and 4.3(3),  and (b) reduced to offset  compensation
          and other  earned  income by  Employee in the manner  provided  for in
          Paragraphs 5.1(2) and 5.1(3) below.

     (2)  The lump-sum  severance  amounts payable to Employee under  Paragraphs
          4.3(1) and 4.3(3)  shall be reduced by one hundred  percent  (100%) of
          any  compensation  and other  earned  income  (within  the  meaning of
          Section  911(d)(2)(A)  of the IRC)  which is  earned by  Employee  for
          services rendered to persons or entities other than the Company or its
          affiliates  during the three years  immediately  following  Employee's
          Termination Without Cause.

     (3)  Not less frequently than annually  beginning on the first  anniversary
          following Employee's Termination Without Cause, Employee shall account
          to the  Company  with  respect to all  compensation  and other  earned
          income  earned by Employee  which is required  hereunder  to be offset
          against the lump-sum  severance  amount  received by Employee from the
          Company under Paragraphs  5.1(1) and 5.1(2). If the Company has paid a
          lump-sum severance amount in excess of the amount to which Employee is
          entitled  (after  giving  effect to the offsets  provided  for above),
          Employee  shall  reimburse  the Company for such excess  within thirty
          (30)  days of the  determination  of  such  excess.  The  requirements
          imposed under this Paragraph  5.1(3) shall terminate  thirty (30) days
          immediately following the third anniversary of Employee's  Termination
          Without Cause.

     5.2 For the purpose of this Agreement, a "Change of Control" shall mean:

     (a) The acquisition by any individual,  entity or group (within the meaning
of Section  13(d)(3) or  14(d)(2) of the  Securities  Exchange  Act of 1934,  as
amended (the "Exchange  Act")(a  "Person") of beneficial  ownership  (within the
meaning  of Rule 13d-3  promulgated  under the  Exchange  Act) of 20% or more of
either  (i) the then  outstanding  shares of common  stock of the  Company  (the
"Outstanding  Company  Common  Stock") or (ii) the combined  voting power of the
then outstanding  voting securities of the Company entitled to vote generally in
the  election  of  directors  (the  "outstanding  Company  Voting  Securities");
provided,  however,  that for purposes of this  subsection  (a),  the  following
acquisitions  shall not  constitute  a Change of  Control:  (i) any  acquisition
directly  from the  Company,  (ii) any  acquisition  by the  Company,  (iii) any
acquisition  by an  employee  benefit  plan  (or  related  trust)  sponsored  or
maintained by the Company or any  corporation  controlled by the Company or (iv)
any acquisition by any corporation pursuant to a transaction which complies with
clauses (i), (ii) and (iii) of subsection (c) of this Section 5.2; or

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     (b)  Individuals  who,  as of the date  hereof,  constitute  the Board (the
"Incumbent Board") cease for any reason to constitute at least a majority of the
Board; provided,  however, that any individual becoming a director subsequent to
the date hereof whose  election,  or  nomination  for election by the  Company's
shareholders,  was  approved by a vote of at least a majority  of the  directors
then  comprising  the  Incumbent  Board  shall  be  considered  as  though  such
individual  were a  member  of the  Incumbent  Board,  but  excluding,  for this
purpose,  any such  individual  whose  initial  assumption of office occurs as a
result of an actual or threatened  election contest with respect to the election
or removal of directors or other actual or threatened solicitation of proxies or
consents by or on behalf of a Person other than the Board; or

     (c)  Consummation of a  reorganization,  merger or consolidation or sale or
other  disposition of all or  substantially  all of the assets of the Company or
the acquisition of assets of another corporation (a "Business Combination"),  in
each case, unless, following such Business Combination, (i) all or substantially
all  of  the   individuals   and  entities  who  were  the  beneficial   owners,
respectively,  of the Outstanding  Company Common Stock and Outstanding  Company
Voting Securities  immediately prior to such Business  Combination  beneficially
own,  directly  or  indirectly,  more  than  50%  of,  respectively,   the  then
outstanding  shares of common  stock and the  combined  voting power of the then
outstanding  voting  securities  entitled to vote  generally  in the election of
directors,  as the case may be, of the corporation  resulting from such Business
Combination (including,  without limitation,  a corporation which as a result of
such transaction  owns the Company or all or substantially  all of the Company's
assets either directly or through one or more subsidiaries) in substantially the
same  proportions  as  their  ownership,  immediately  prior  to  such  Business
Combination  of the  Outstanding  Company Common Stock and  Outstanding  Company
Voting Securities, as the case may be, (ii) no Person (excluding any corporation
resulting  from such  Business  Combination  or any  employee  benefit  plan (or
related trust) of the Company or such  corporation  resulting from such Business
Combination)  beneficially  owns,  directly  or  indirectly,  20%  or  more  of,
respectively,  the then  outstanding  shares of common stock of the  corporation
resulting  from such Business  Combination  or the combined  voting power of the
then outstanding voting securities of such corporation except to the extent that
such ownership  existed prior to the Business  Combination  and (iii) at least a
majority of the members of the board of directors of the  corporation  resulting
from such Business  Combination  were members of the Incumbent Board at the time
of the  execution  of the  initial  agreement,  or of the  action of the  Board,
providing for such Business Combination; or

     (d) Approval by the  shareholders of the Company of a complete  liquidation
or dissolution of the Company.

     5.3 Certain Additional Payments by the Company may be due as follows:

     (a) Anything in this Agreement to the contrary  notwithstanding  and except
as set forth  below,  in the event it shall be  determined  that any  payment or
distribution  by the  Company  or its  affiliates  to or for the  benefit of the
Employee  (whether paid or payable or distributed or  distributable  pursuant to
the terms of this  Agreement or otherwise but  determined  without regard to any
additional  payments  required  under this Section 5.3), (a "Payment")  would be
subject to the excise tax imposed by Section 4999 of the Code or any interest or
penalties  are  incurred by the  Employee  with respect to such excise tax (such
excise tax,  together  with any such  interest and  penalties,  are  hereinafter
collectively  referred  to as the  "Excise  Tax"),  then the  Employee  shall be
entitled to receive an  additional  payment (a "Gross-Up  Payment") in an amount
such that after payment by the Employee of all 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, the Employee retains an amount
of the  Gross-Up  Payment  equal to the Excise Tax  imposed  upon the  Payments.
Notwithstanding  the  foregoing  provisions  of this Section 5.3, if it shall be
determined  that the  Employee is entitled to a Gross-Up  Payment,  but that the
Payments do not exceed 110% of the greatest  amount (the "Reduced  Amount") that
could be paid to the Employee  such that the receipt of Payments  would not give
rise to any Excise Tax,  then no Gross-Up  Payment shall be made to the Employee
and the Payments, in the aggregate, shall be reduced to the Reduced Amount.

     (b)  Subject  to the  provisions  of  Section  5.3(c),  all  determinations
required  to be made  under  this  Section  5.3,  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
Ernst and Young or

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such other certified public accounting firm as may be designated by the Employee
(the  "Accounting  Firm") which shall provide detailed  supporting  calculations
both to the Company and the Employee  within 15 business  days of the receipt of
notice from the Employee that there has been a Payment,  or such earlier time as
is requested by the Company. In the event that the Accounting Firm is serving as
accountant or auditor for the  individual,  entity or group effecting the Change
of Control, the Employee shall appoint another nationally  recognized accounting
firm to make the determinations  required hereunder (which accounting firm shall
then be referred to as the Accounting Firm hereunder).  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 5.3, shall be paid by the Company to the
Employee within five days of the receipt of the Accounting Firm's determination.
Any  determination  by the Accounting Firm shall be binding upon the Company and
the Employee.  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  Company
exhausts its remedies pursuant to Section 5.3(c) and the Employee  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 Company to or for the benefit of the
Employee.

     (c) The  Employee  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 business  days after the Employee is informed
in  writing 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.  The  Employee
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 the Employee in writing prior to the expiration of such
period that it desires to contest such claim, the Employee shall:

     (i) give the Company any  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,

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

     (iv) 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 Employee  harmless,  on an
after-tax  basis,  for 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 expenses. Without limitation on the foregoing provisions of
this  Section  5.3(c),  the  Company  shall  control  all  proceedings  taken in
connection  with such contest  and, at its sole option,  may pursue or forgo 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  Employee  to pay the tax claimed and sue for a refund or contest the
claim in any  permissible  manner,  and the Employee  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 if the Company directs the Employee to pay
such claim and sue for a refund,  the Company  shall  advance the amount of such
payment to the Employee,  on an interest-free basis and shall indemnify and hold
the Employee harmless,  on an after-tax basis, from any Excise Tax or income tax
(including  interest or penalties with respect  thereto) imposed with respect to
the 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 the taxable year of the  Employee  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-

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Up Payment would be payable  hereunder  and the Employee  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  receipt by the  Employee  of an amount  advanced by the
Company pursuant to Section 5.3(c), the Employee becomes entitled to receive any
refund with respect to such claim,  the Employee shall (subject to the Company's
employing with the  requirements  of Section 5.3 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 Employee of an amount
advanced by the Company pursuant to Section 5.3(c), a determination is made that
the Employee  shall not be entitled to any refund with respect to such claim and
the  Company  does not notify the  Employee  in writing of its intent to contest
such  denial  of  refund  prior  to  the   expiration  of  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.

6. Covenants.

     6.1 Employee agrees that any and all confidential knowledge or information,
including but not limited to customer lists,  books,  records,  data,  formulae,
specifications,   inventions,   processes  and  methods,  and  developments  and
improvements,  which have been or may be  obtained or learned by Employee in the
course  of his  employment  with  the  Company,  will  be held  confidential  by
Employee, and that Employee shall not disclose the same to any person outside of
the  Company  either  during  his  employment  with the  Company  or  after  his
employment by the Company has terminated.

     6.2  Employee  agrees  that upon  termination  of his  employment  with the
Company he will  immediately  surrender  and turn over to the Company all books,
records,  forms,  specifications,  formulae,  data,  and all papers and writings
relating to the business of the Company and all other property  belonging to the
Company,  it being  understood and agreed that the same are the sole property of
the Company and that Employee shall not make or retain any copies thereof.

     6.3 Employee agrees that all inventions, developments or improvements which
he has made or may make, conceive,  invent, discover or otherwise acquire during
his  employment  with  the  Company  in the  scope  of his  responsibilities  or
otherwise shall become the sole property of the Company.

     6.4  Employee  agrees to provide a release of any  claims  with  respect to
termination  of his or her  employment  on such form as requested by the Company
upon payment of the sums provided in Section 4.3 above.

7. Miscellaneous Provisions.

     7.1 All terms and  conditions of this  Agreement are set forth herein,  and
there are no  warranties,  agreements  or  understandings,  express or  implied,
except those expressly set forth herein.

     7.2 Any  modification  to this Agreement shall be binding only if evidenced
in writing signed by all parties hereto.

     7.3 Any notice or other  communication  required or  permitted  to be given
hereunder shall be deemed properly given if personally delivered or deposited in
the United States mail,  registered or certified and postage prepaid,  addressed
to the Company at 2141 Rosecrans  Ave.,  Suite 4000, El Segundo,  CA (Attention:
General Counsel),  or to Employee at his or her most recent home address on file
with Company,  or at other such addresses as may from time to time be designated
in writing by the respective parties.

     7.4 The laws of the State of  California  shall govern the validity of this
Agreement,  the construction of its terms, and the  interpretation of the rights
and duties of the parties involved.

     7.5 In the event that any one or more of the  provisions  contained in this
Agreement shall for any reason be held to be invalid,  illegal or unenforceable,
the same shall not affect any other provision of this Agreement, but

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this Agreement shall be construed as if such invalid,  illegal or  unenforceable
provisions had never been contained herein.

     7.6 This Agreement  shall be binding upon, and inure to the benefit of, the
successors  and assigns of the Company and the personal  representatives,  heirs
and legatees of Employee.

     7.7  "Bonus"  refers  to the  Unocal  Incentive  Compensation  Plan and any
replacement or successor plan thereof.

     7.8 Company  shall pay 90% (ninety  percent)  of  Employee's  out-of-pocket
litigation expenses,  including  reasonable  attorney's fees, in connection with
any judicial  proceeding to enforce this  Agreement or construe or determine the
validity of this  Agreement,  whether or not the Employee is  successful in such
proceeding.

     7.9 The term "Company" shall include with respect to employment  hereunder,
any  subsidiary  or affiliate of the Company as well as any  successor  employer
following a Change in Control.

     7.10 This Agreement succeeds and replaces that Unocal Employment  Agreement
which was effective July 28, 1998 between Company and Employee.


IN WITNESS WHEREOF, the parties have executed this Agreement effective as of the
date first above written.



BY:      /s/ FRANK C. HERRINGER
         ----------------------
         Chairman of the Management Development and
         Compensation Committee of the Unocal
         Board of Directors



BY:      /s/ CHARLES R. WILLIAMSON
         -------------------------
         EMPLOYEE

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