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                                                                   EXHIBIT 10.20

                      SUMMARY OF ENHANCED SEVERANCE PROGRAM

On December 5, 2000, the boards of directors of Unocal Corporation and its Union
Oil Company of California subsidiary (collectively, the "Company) have approved
an enhanced severance program for approximately 2,800 U.S.-payroll employees not
represented by collective bargaining agents in the event they lose their jobs
through a change of control of the Company on or prior to December 31, 2004.

In the event of a "change of control" of the Company, as defined in Section 2(e)
of the Company's Long-term Incentive Plan of 1998, the program provides for the
immediate vesting of accrued benefits and/or accounts of all covered employees
under the Company's retirement and savings plans and the immediate payment to
such employees in cash of bonuses under its annual incentive compensation plans.

The following additional provisions of the program become operative in the event
of an employee's involuntary termination of employment (other than for death,
disability or misconduct) or constructive discharge within two years following a
change of control. "Constructive discharge" includes an employee's resignation
within 60 days following certain reductions in pay, benefits and/or perquisites,
or as a result of certain work location changes.

The program provides four months of base pay for all eligible employees,
regardless of years of service. Employees with at least five years of service
also would receive credit for an additional three years of service and three
years of age under the Company's retirement plans plus the incremental
difference in value, if any, of three-fourths of a month of base pay for each
completed year of actual service, to a maximum of 20 months, above the
discounted present value of the enhancement to the retirement benefit. Employees
with less than five years of service would receive the three-fourths of a month
of base pay for each completed year of service. Executive officers holding
employment agreements would be entitled to the enhanced benefit if they agree
to its offset against the change-of-control benefits already provided under such
agreements.

The program permits an eligible employee to elect an immediate distribution or
rollover of his or her total retirement plan benefits, as enhanced (the amount
of which would be based on the highest consecutive 12 months of pensionable pay
during the most recent 120 months of service). The program also provides for
subsidized "COBRA" medical and dental coverage for 18 months, a "three plus
three" enhancement to criteria for determining eligibility and contributions
under the Company's retiree and special continuation medical coverages and for
determining eligibility under its retiree life and AD&D insurance plans, as well
as certain other benefits.

The program includes a "tax gross-up" arrangement for employees subject to the
excise tax provided for by Section 280G of the Internal Revenue Code. Under this
section, excise taxes are imposed on employees receiving change-of-control
payments (as defined) that exceed 2.99 times the employee's average annual
compensation (as defined). Under the arrangement, an employee who is subject to
the excise tax would receive a gross-up payment, in addition to the amounts
deemed change-of-control payments, to eliminate the effect of the excise tax.
This gross-up arrangement would apply only if the employee's change-of-control
payments exceed the excise tax threshold amount of Section 280G by more than 10
percent. Otherwise, such payments would be reduced below the threshold.