EXHIBIT 10


                 AGREEMENT AND GENERAL RELEASE
                 -----------------------------


This AGREEMENT AND GENERAL RELEASE, executed this 6th day of November, 2002, by
and between Dennis P.R. Codon (hereinafter referred to as "Employee"), and Union
Oil Company of California (hereinafter referred to as "Company") and Unocal
Corporation (hereinafter referred to as "Unocal").

     WHEREAS, Employee is currently employed by Company and located in El
Segundo, California and is an officer of Company and Unocal;
     WHEREAS, Employee, Company and Unocal wish to end his employment with
Company and his status as an officer of Unocal and Company if certain conditions
are satisfied.

     WHEREAS, Employee, Company and Unocal have determined they wish to resolve
all issues regarding Employee's employment and termination thereof.

     NOW, THEREFORE, in consideration of the mutual promises contained in this
AGREEMENT AND GENERAL RELEASE, the sufficiency of which are hereby acknowledged,
Company, Unocal and Employee agree as follows:

          1.   Employee  shall  resign  as an  officer  of  Unocal  and  Company
               effective  December  31, 2002 or such earlier date as is mutually
               acceptable to the parties.

          2.   Employee shall be a "Consulting  Employee" for the period January
               1, 2003 (or the effective  date following his  resignation  under
               paragraph if earlier) through September 30, 2003 (the "Employment
               Period") reporting to the Chief Executive Officer of Unocal. As a
               Consulting -- Employee, Employee shall continue to be an Employee
               for all  purposes.  During the  Employment  Period  Employee will
               continue  to be paid his  current  base  salary,  accrue  benefit
               service under the Unocal  Retirement Plan and otherwise  continue
               to be  eligible  for the  Company's  benefit  plans  such as 401k
               contributions,  health  insurance,  vacation  pay,  etc. that are
               generally applicable to full time employees at his current salary
               grade. Thereafter,  Employee and his dependents shall be eligible
               to receive all  retiree  health and  welfare  benefits  generally
               applicable  to  a  Company  employee  in  Employee's   employment
               category.  During the  Employment  Period,  Employee shall not be
               adversely  affected by an amendment to retiree or retiree medical
               benefits,  including without  limitation the amount of Employee's
               Pension Bonus Service under the Unocal  Retirement  Plan,  except
               where  such   amendment   would  also  apply  to  senior  Company
               executives.

          3.   Employee  shall be paid his accrued  but untaken  vacation in the
               approximate amount of $62,000  (Sixty-two  Thousand Dollars) less
               applicable  withholding on or before  January 15, 2003.  Employee
               shall accrue  additional  vacation  while a Consulting  Employee,
               which shall be paid on or before October 15, 2003.

          4.   Employee  shall  be  eligible  to  receive  financial  counseling
               services  at  Company  expense  through   December  31,  2003  in
               accordance with existing Company policies,

          5.   Employee  shall  be  eligible  to  receive  a  Revised  Incentive
               Compensation  Plan Award for calendar year 2002. Said award shall
               be determined based on the percentage of target awards payable to
               corporate  department  employees  of Company in salary grade X-08
               based on Company  performance  but  without  any  adjustment  for
               individual performance.

          6.   For Calendar year 2003 Employee  shall be entitled to the greater
               of  (a)  75%  (seventy-five)  percent  of the  Revised  Incentive
               Compensation Award that would be payable to corporate  department
               employee in salary  grade X-08 based on Company  performance  but
               without any  adjustment  for  individual  performance  or (b) 75%
               (seventy-five   percent)   of  the   target   Revised   Incentive
               Compensation  Plan  Award for an  employee  in salary  grade X-08
               without adjustment for Company or individual performance.

          7.   During the Employment  Period  Employee may perform  services for
               others  so long as  Employee  remains  reasonably  available  for
               telephonic  consulting and such services do not conflict with the
               obligations of paragraph 16 below.  Employee  agrees that he will
               resign as a Consulting  Employee in the event he becomes employed
               by a  company  in the  business  of oil and gas  exploration  and
               production  or by a government  body that  regulates or otherwise
               has oversight  over the  activities of the Company.  In the event
               Employee  resigns as a  Consulting  Employee  or dies  during the
               Employment  Period, he shall be paid the remaining portion of his
               base  salary  for said  period in a single  sum within 30 days of
               such resignation.

          8.   Employee  shall   terminate  his  employment   with  the  Company
               effective  October 1, 2003,  unless he has resigned prior to such
               date.

          9.   Employee shall receive the sum of $1,415,522  (One Million,  four
               Hundred  fifteen  Thousand Five Hundred and  Twenty-two  Dollars)
               less applicable withholding on or before March 30, 2003.

          10.  Employee's   termination  of  employment   shall  not  be  deemed
               "Voluntary" or "For Cause" under that Promissory Note dated as of
               March 16, 2000.  Therefore,  the  acceleration of the payment due
               date under said Promissory Note to 60 days following  termination
               of employment shall not be applicable to Employee.

          11.  Employee's termination of employment, shall be treated as "at the
               convenience of the Company"  pursuant to the Long-Term  Incentive
               Plan of  1991,  the  Long-Term  Incentive  Plan  of 1998  and the
               Revised Incentive Compensation Plan. Therefore, Employee shall be
               entitled to the delivery of shares of Restricted  Stock,  payment
               of Performance  Shares and the extended period to exercise vested
               stock  options  applicable  under the terms of said  Plans upon a
               termination of employment at the convenience of the Company.  The
               amount of the Employee's vested stock options, performance shares
               and  restricted  stock,  as well as a  pro-ration  of such awards
               resulting  from his  termination  are  indicated in Attachment A,
               assuming he remains a Consulting  Employee through the Employment
               Period.  Other  than the  calendar  year 2002  Revised  Incentive
               Compensation  Plan Award,  Employee  shall not receive  awards of
               grants under the Long-Term  Incentive  Plan of 1998,  the Revised
               Incentive Compensation Plan, the Annual Incentive Plan or similar
               plan of the  Company  after  December  31,  2002.  This shall not
               affect his rights with respect to awards granted prior thereto.

          12.  Employee   shall  be  paid  the   account   balances   under  the
               Supplemental Savings Plan as indicated on Section I of Attachment
               A,  including  accrued  interest  to  December  31,  2002 and the
               deferred cash portion of the Revised Incentive  Compensation Plan
               ("ICP") awards as indicated in Attachment A.

          13.  In  the  event  a  transaction  is  publicly  announced  that  if
               completed  would  constitute  a "Change of Control" of Unocal (as
               defined in the Long-Term Incentive Plan of 1998) prior to October
               1, 2003 and a Change of Control of Unocal is  consummated  by any
               party or parties  prior to October  1, 2005 then  Employee  shall
               receive the sum of $911,970  (Nine  Hundred and Eleven  Thousand,
               Nine  Hundred  and Seventy  Thousand  Dollars),  less  applicable
               withholding, payable within 60 days of said Change of Control.

          14.  Employee  shall  not  be  entitled  to any  other  severance-type
               benefits,  including  without  limitation,   Unocal  Redeployment
               Program or Unocal Termination Allowance Plan benefits,  except as
               specifically  noted above.  Employee shall not be entitled to any
               payments under the Unocal Employee  Agreement dated July 28, 1998
               by and  between  Employee  and Unocal  Corporation.  The  parties
               understand  that this  Agreement  and  General  Release is a full
               settlement  of all of  Employee's  rights  under said  Employment
               Agreement.

          15.  Employee has been granted a Performance  Bonus Award  pursuant to
               the  Long-Term  Incentive  Plan of 1998 and as a  recipient  of a
               Unocal 2000 Executive  Stock Purchase  Program Award.  Employee's
               termination will be treated thereunder as other than a "Voluntary
               Termination" or a "Termination  for Cause".  Therefore,  Employee
               will be entitled to payment of a  Performance  Bonus as if he had
               remained in employment  during the full Award  Period,  including
               without  limitation  any  payment  under the  Change  Of  Control
               provisions thereof. He shall be treated in the same manner as any
               other  recipient  of  a  Performance  Bonus  Award  who  did  not
               terminate employment during the Award Period. Notwithstanding the
               above,  Employee  shall be treated no less favorably with respect
               to the Unocal 2000 Executive  Stock Purchase  Program,  including
               the loan  thereunder,  as any other employee who  participated in
               the program.

          16.  All  technical,  business  or other  information,  including  all
               documents,  material and  intellectual and tangible work product,
               which is  developed  or received by Employee in  connection  with
               Employee's  work  hereunder,  or which  is or has been  otherwise
               disclosed to Employee by Company either orally or in writing,  is
               the  exclusive  property  of  Company,  and  Employee  agrees  to
               maintain such  information  in strict  confidence  and not to use
               such  information  other than in work for Company.  The foregoing
               shall not apply to information which Employee can show either (i)
               is  already  known to  Employee  other  than as a result  of work
               performed hereunder or from prior work for the Company (ii) is or
               becomes part of the public domain, other than by Employee's fault
               or (iii) is required to be disclosed by applicable law.

               Employee's   obligations   under  this  paragraph  shall  survive
               termination   of   this    Agreement.

          17.  GENERAL RELEASE
               ---------------

               Except for the rights of Employee hereunder, in consideration for
               this Agreement,  Employee hereby releases and forever  discharges
               Company and Unocal Corporation and their respective predecessors,
               successors, partners, assigns, employees,  shareholders,  owners,
               officers, directors, agents, attorneys, subsidiaries,  divisions,
               and affiliates  (jointly referred to as "Released  Parties") from
               any and all  claims,  demands,  causes  of  action,  obligations,
               damages,  attorneys'  fees,  costs and  liabilities of any nature
               whatsoever,  whether or not now  known,  suspected  or  asserted,
               which  Employee  may have or claim to have  against the  Released
               Parties relating in any manner to Employee's  employment with the
               Company  and/or the  termination of such  employment,  and hereby
               covenants  not to  assert  such  claims  through  a  lawsuit,  an
               administrative  proceeding  or  otherwise.  This General  Release
               includes,  but is not limited to, claims  arising under  federal,
               state or local  laws  prohibiting  employment  discrimination  or
               claims  arising out of any legal  restrictions  on the  Company's
               rights to terminate its employees,  including without  limitation
               of the Age Discrimination in Employment Act of 1967, Title VII of
               the Civil Rights Act of 1964, and the Civil Rights Act of 1991.

               Except as specifically provided herein, nothing in this Agreement
               shall affect in any way,  apply to,  increase,  or diminish,  any
               rights which Employee has with respect to retirement  benefits or
               with respect to any previously established policy or plans of the
               Company outside of this Agreement.

               This  Agreement  shall not in any way limit  Employee's  right to
               assert claims,  including  through a lawsuit,  for the actions of
               the  Released  Parties  that  occur  subsequent  to the date this
               Agreement is executed by the  parties,  except to the extent such
               actions of Released  Parties are  expressly  provided for in this
               Agreement.



          18.  Waiver
               ------

               Employee  waives all rights under  Section 1542 of the Civil Code
               of California. That section reads as follows:

                    "A  general  release  does not  extend to  claims  which the
                    creditor  does not know or  suspect to exist in his favor at
                    the time of  executing  the  release,  which if known by him
                    must  have  materially  affected  his  settlement  with  the
                    debtor."

               Notwithstanding the provisions of Section 1542 or any similar law
               of any other state, and to provide a full and complete release of
               Released  Parties,  Employee  expressly  acknowledges  that  this
               Retention  Agreement and General  Release is intended to include,
               without  limitation,  all claims which  Employee does not know or
               suspect  to exist in his favor at the time of  execution  of this
               document,   and  that  the  settlement   agreed  upon  completely
               extinguishes all such claims.

          19.  Employee  shall not disclose  the terms of this  Agreement to any
               third  party,  including  current  or  former  employees  of  the
               Company,   except  for  those   employees  who  are  involved  in
               administering  matters  related to or arising in connection  with
               this  Agreement.  In the  event of any  unauthorized  disclosure,
               Company may immediately  terminate Employee's  employment without
               any penalty or any obligation  under this Agreement.  The Company
               will only invoke  this  provision  on  compelling  evidence  that
               Employee has intentionally  breached the foregoing provision.  At
               the time of execution of this  Agreement,  Company agrees that it
               has no knowledge of any  unauthorized  disclosure  by Employee as
               such disclosure is referred to in this paragraph.

               Notwithstanding   the  foregoing,   Employee  may  disclose  this
               Agreement to his  attorney,  accountant,  tax advisor,  spouse or
               spouse's  attorney  (after first  instructing  them and obtaining
               their  agreement to not disclose this  Agreement to others except
               as required by law or professional  rules) as well as to taxation
               authorities and as required by law.

          20.  In addition to any indemnification obligations Company has or may
               have under applicable law,  Company shall indemnify  Employee for
               any  and  all  costs,  expenses,   awards,   claims,   judgments,
               attorneys;  fees or any other  damages or injury to Employee  for
               Employee's actual or alleged actions or failure to act during his
               employment  with Company  including  Employee's  employment  as a
               Consulting Employee,  unless Company under its standard policy on
               such  matters  would not have so  indemnified  Employee  for such
               actions or failure to act were he still actively  employed at his
               current salary level and position.

          21.  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,  if the Employee is  substantially  successful in
               such proceeding.


          22.  This  AGREEMENT  AND  GENERAL  RELEASE  is a  full  and  complete
               expression  of the  intent of the  parties  with  respect  to the
               subject  matter  of  this   Agreement.   No  other  agreement  or
               representation, express or implied, has been made by either party
               with respect to the subject matter of this Agreement.

          23.  This AGREEMENT AND GENERAL  RELEASE may not be modified except by
               a  written  agreement  signed  by  both  Employee  and  by a Vice
               President of Union Oil Company of California.

          24.  This  AGREEMENT AND GENERAL  RELEASE shall be  interpreted  to be
               valid to the full extent  possible under the laws of the State of
               California.

          25.  Employee  warrants and represents  that he has not assigned or in
               any way  transferred  any claim related to the subject  matter of
               this AGREEMENT AND GENERAL  RELEASE and that he will not allow or
               assist in such transfer or assignment in the future.

          26.  This  AGREEMENT  AND  GENERAL  RELEASE  shall not  constitute  an
               admission  by any  Released  Party  of  any  wrongful  action  or
               inaction whatsoever.

          27.  Company may not assign  this  Agreement,  except  that  Company's
               obligations  hereunder  shall be  binding  legal  obligations  of
               Company  and  Unocal  Corporation  and  any  successor  to all or
               substantially all their business by sale,  merger,  consolidation
               or otherwise.

          28.  Employee  agrees  that this  AGREEMENT  AND  GENERAL  RELEASE  is
               understood  by Employee  and is  voluntarily  entered into by the
               Employee.

          29.  The payments and benefit provided under paragraphs 3, 7, 9 and 13
               shall be payable even in the event of  Employee's  death prior to
               receipt  thereof.   Employee  may  file  a  written   beneficiary
               designation  for any such  payments in the form of  Attachment C.
               The last such designation  received by Company prior to his death
               shall  control  any  such  payments.  In the  absence  of a valid
               election,  payments  shall be made to Employee's  estate or legal
               representative.

          30.  Employee  acknowledges  that he has been  advised of his right to
               consult with an attorney  regarding the effect of this  Agreement
               prior to signing it.  Employee  has been  advised of his right to
               take at least  twenty-one  (21)  days to study  and  review  this
               Agreement  before signing.  Employee also  understands he has the
               right to revoke this  Agreement  for seven (7) days after signing
               it.  If  signed  by both  parties,  this  Agreement  will  become
               effective upon the end of said seven (7) day period.

          31.  This  Agreement  shall be construed  as a whole  according to its
               fair meaning.  It shall not be construed  strictly for or against
               Employee,  Company  or  any  Release.  This  Agreement  shall  be
               governed  by  the  statutes  and  common  law  of  the  State  of
               California.


     IN WITNESS WHEREOF, this AGREEMENT AND GENERAL RELEASE has been executed in
duplicate originals.

UNION OIL COMPANY OF CALIFORNIA
 AND UNOCAL CORPORATION


By: /S/Timothy Ling
      ------------

                             /s/  Dennis P.R. Codon
                                  -----------------
                                  Signature

                                  Dennis P.R. Codon
Timothy Ling                      -----------------
- ------------                      Print Name
Print Name
                                  November 6, 2002
November 6, 2002                  ----------------
- ----------------                  Date
Date





                  ATTACHMENT A TO AGREEMENT AND GENERAL RELEASE


     I.                   ICP Cash Deferred
                          -----------------

              $ 10,000.00           1998 ICP Deferral
              $  2,880.35           Interest Earned thru 9/30/02
              ------------

              $ 12,880.35           Balance as of 9/30/02

              $140,000.00          2001 ICP Deferral
              $ 15,814.97          2002 Salary Deferred to Date
              $  7,675.62          Interest Earned thru 9/30/02
              ------------
              $163,490.59          Balance as of 9/30/02
              -----------

              $176,370.94          Total



     II.                Supplemental Savings Plan
                        -------------------------

                                                                     Balance
                     Accrued          Accrued Co.      Accrued    through Cycle
         Year        Principal         Contribution    Interest       2002-21

         1997        $  6,460.00                       $    0.00
         1998        $  7,400.16                       $  635.09
         1999        $  8,200.32                       $1,105.34
         2000        $  9,900.24                       $2,221.87
         2001        $ 12,150.24                       $2,905.45
         2002        $  6,356.07        $621.88        $3,091.65    ___________
                     -----------        -------        ---------

           Total     $ 50,467.03        $621.88        $9,959.40    $61,048.31















                  ATTACHMENT C TO AGREEMENT AND GENERAL RELEASE

                             BENEFICIARY DESIGNATION
                             -----------------------



I, Dennis P.R.Codon, (Employee) hereby designate the following person(s) as
Beneficiary for any payments due at the time of my death under Sections 2, 4, 5,
6, 8 and 11 of my AGREEMENT AND GENERAL RELEASE with Union Oil Company of
California, dba Unocal.



Name:                        __________________________


Address:                __________________________


Relationship:           __________________________


Interest (%):           __________________________



Name:                   _______________________________


Address:           _______________________________


Relationship:      _______________________________


Interest (%):      _______________________________









codonagrmt.doc