Exhibit 10.1

                          Retention Payment Agreement
                          ---------------------------

This Retention Payment Agreement (hereafter referred to as "Agreement"), is by
and between Mr. Joe D. Cecil (hereafter referred to as "Employee"), and Union
Oil Company of California (hereafter referred to as "Company").

In consideration of the mutual promises contained in this Agreement, the receipt
and sufficiency of which are hereby acknowledged, Company and Employee agree as
follows:

                                    Section 1

Employee must satisfy all of the following conditions in order to receive the
Retention Payment:

     1.   Employee  remains an  Employee of the  Company  through and  including
          March 31, 2005; and

     2.   Employee performs all of Employee's  assigned job  responsibilities in
          at least a satisfactory manner, in the sole good-faith judgment of the
          Management Committee; and

     3.   Employee  complies with all  applicable  Company  policies in the sole
          good-faith judgment of the Management Committee.

     4.   Employee's  employment with the Company voluntarily  terminates at the
          convenience of the company by early retirement on April 1, 2005.

                                    Section 2

If the Employee becomes eligible for a Retention Payment, the amount of the
Retention Payment shall be Two Hundred eighty-five Thousand United States
Dollars and No Cents ($285,000.00), less applicable taxes and other withholding
required by law.

The Retention Payment shall be paid in a single sum on April 1, 2005.

The Retention Payment shall not increase Employee's benefits under any other
benefit plan or compensation program of the Company, including, without
limitation, the Unocal Retirement Plan, the Unocal Savings Plan, the Unocal
Annual Incentive Program, the Unocal Incentive Compensation Plan, Stock Options,
Performance Shares, or Restricted Stock. Further, the Retention Payment shall
not be eligible for deferral into the Unocal Deferred Compensation Plan unless
the Unocal Deferred Compensation Plan is amended to allow the inclusion of
Retention Payments prior to payment of the Retention Payment.

                                    Section 3

For the time period beginning April 1, 2005 through and including March 31,
2006, Employee will be reasonably available to answer questions from the Company
or the Company's representatives via telephone and e-mail. Company and Employee
anticipate that the amount of time per month will be 15 hours, more or less.
However, in the event of a an inquiry regarding calendar year 2004, the number
of telephone and email hours noted above may be substantially exceeded and
employee shall also be reasonably available from time to time to come to the
company office in El Segundo, California to assist regarding responses to such
inquiry. Even if such additional services are needed, Employee shall not receive
any compensation in addition to the Retention Payment for providing such
services except for the reasonable documented expenses incurred in the
performance of such services for the company in accordance with the company's
expense account policy. Employee shall not be reimbursed for commuting expenses
from home to the El Segundo office.

                                    Section 4

This Agreement 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.

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                                    Section 5

This Agreement does not modify the provisions of any other written agreement
between an authorized representative of Company and Employee.

                                    Section 6

This Agreement may not be modified except by a written agreement signed by
Employee and by Company's Chief Financial Officer.

                                    Section 7

This Agreement shall be governed by the laws of the state of California
(excluding California' choice of law rules), shall be interpreted to be valid to
the full extent possible under California law and shall not be construed against
any party.

IN WITNESS WHEREOF, this Retention Payment Agreement has been signed in
duplicate originals.


UNION OIL COMPANY OF CALIFORNIA     (Company)

Signature:  /s/ Terry G. Dallas
            -------------------
Print Name: Terry G. Dallas
Title:  Executive Vice President & Chief Financial Officer
Date:   December 29, 2004


JOE D. CECIL (Employee)

Signature:  /s/ Joe D. Cecil
            ----------------
Print Name: Joe D. Cecil
Title:  Vice President & Comptroller
Date:   December 29, 2004

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