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                                                                    EXHIBIT 10.3

                                                                  CONFORMED COPY





                                 WESTLAKE GROUP

                              PERFORMANCE UNIT PLAN


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                            EFFECTIVE JANUARY 1, 1991



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                                                                    CONFIDENTIAL



                                 WESTLAKE GROUP

                              PERFORMANCE UNIT PLAN

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                            EFFECTIVE JANUARY 1, 1991


1.0 PURPOSE

         1.1      The objective of the Westlake Group Performance Unit Plan (The
                  Plan) is to reward selected Key Employees with a piece of the
                  future of the Company whose value the Key Employees help to
                  enhance.

         1.2      The Plan is designed to provide selected Key Employees with a
                  sense of ownership in the Company and an opportunity to
                  benefit from the increase in the value of the Company and thus
                  to aid in attracting and retaining Key Employees.

2.0 ADMINISTRATION

         2.1      The Chairman's Office (CO) shall have total and complete
                  discretion to determine who receives Performance Units (PUs);
                  the amount and value of PUs; and the time of issuance of PUs.

         2.2      No decision by CO shall be considered an ongoing rule or
                  regulation unless so expressly stated by CO.

         2.3      Decisions and determinations of CO shall be final and binding
                  on all parties.

3.0 VALUATION OF PUs

         3.1      PU will be assigned a base value of $1.00.

         3.2      PU will entitle Key Employee (when eligible to exercise) to a
                  payment measured as follows:

<Table>
<S>               <C>
                               Book Value at Exercise Valuation Date -- Book Value at Grant Date
                  Cash Value = ----------------------------------------------------------------- x $1.00 x # of Vested Units
                                                   Book Value at Grant Date
</Table>

         3.3      Book Value to be defined by CO and determined on an annual
                  basis and shall exclude any new infusions of capital or
                  increases in capital through any mergers with any other
                  company during the period between the grant date and the date
                  of exercise.

         3.4      Each new grant will be based upon the book value as of the
                  date of the new grant.


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         3.5      At the discretion of the CO, a dividend may be withdrawn at
                  any time which may reduce the original book value base for any
                  grant year. To maintain the same growth ratio as if the
                  dividend had been left in the business, the following ratio
                  will be applied to the book value at the exercise date. In the
                  event of multiple dividend withdrawals during the life of the
                  grant, this ratio will be applied each time so that the rate
                  of growth that otherwise may have occurred without the
                  withdrawals will remain the same.

                    Ratio (R) =  Book Value Before Dividend Withdrawal (W/D)
                                 -------------------------------------------
                                    Book Value Before W/D  --  W/D Amount

4.0 EXERCISE OF PU RIGHTS

         4.1      Vested PUs can only be converted to cash during April of each
                  calendar year.

         4.2      Conversion of PUs to cash extinguishes all rights associated
                  with such converted PUs.

         4.3      Upon an initial public offering of stock in any Westlake
                  companies, a participant will be allowed to convert the value
                  of unexercised PUs into common stock on a basis more favorable
                  than the public offering price as determined by CO.

5.0 VESTING & AWARD CONDITIONS

         5.1      50% of PUs awarded in each grant shall be vested 2 years after
                  the date of award (vesting date) if the employee is still
                  employed by Westlake at such time. Vested PUs are exercisable
                  in any April following the vesting date.

         5.2      Remaining 50% of PUs awarded in each grant shall be vested 7
                  years after date of award if employee is still employed by
                  Westlake at such time. Vested PUs are exercisable in any April
                  following the vesting date.

         5.3      Key employees awarded PUs under the 1990 grant of the plan
                  shall be vested in 50% of PUs after 1 year from the date of
                  award and 50% after 6 years. All subsequent grants will follow
                  the vesting schedule above.

         5.4      If employment of participant terminates other than for death,
                  disability, or normal retirement, participant may only
                  exercise any vested PUs during the next exercise period.
                  Failure to exercise during the next exercise period will
                  result in the forfeiture of vested PUs.

         5.5      All non-vested PUs held at termination of employment except in
                  the case of death or disability or normal retirement shall be
                  forfeited.

         5.6      Upon total and permanent disability as determined by CO or
                  upon death or normal retirement of a participant, all PUs
                  become vested immediately and shall be automatically exercised
                  during the next exercise period. In the case of death, the
                  proceeds will be distributed to the participant's designated
                  beneficiary.


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         5.7      All PUs must be exercised within 10 years of award pursuant to
                  IRS guidelines.

6.0 CHANGE OF OWNERSHIP

         6.1      In case of more than a 50% change in ownership of the stock or
                  underlying assets of Westlake, a provision in the plan as
                  determined by the CO will protect the rights of participants
                  in previously granted awards, or the plan may be terminated
                  with all outstanding vested units becoming eligible for
                  exercise at a date as determined by CO.

7.0 LIMITATION OF LIABILITIES

         7.1      CO reserves the right at any time to amend or terminate the PU
                  Plan; but such action shall not adversely affect any plan
                  participant (or beneficiary) with respect to vested PUs
                  previously awarded and then any outstanding units at such
                  termination will become exercisable at a date as determined by
                  CO.

         7.2      CO and Westlake Group of Companies shall not be liable to plan
                  participants or beneficiaries for any decision, action or lack
                  of action taken in connection with the PU Plan.

         7.3      The Plan shall not establish any right on the part of
                  employees to receive PUs except as solely determined by CO.

         7.4      The Plan shall not give any employee or any other persons any
                  rights or interest in any specific asset or assets of a
                  Westlake Company.

         7.5      The Plan shall not in any way be evidence of any agreement or
                  understanding, express or implied, that a Westlake Company
                  will employ a plan participant in any particular position or
                  at any specific rate of pay.

8.0 TAX CONSIDERATIONS

         8.1      Company is not allowed a current deduction for awards of PUs
                  based upon current IRS guidelines.

         8.2      Employees have no taxable income until PUs are exercised or
                  deemed exercised at date of expiration.

         8.3      Company gets a tax deduction for its taxable year which
                  includes last day of employee's tax year in which the
                  employee's payments becomes taxable.


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9.0 BENEFICIARY

         9.1      Each participant should select a beneficiary to receive
                  payments payable at the first exercise period following the
                  Key Employee's death.



                                      APPROVED:      /s/ James Chao
                                                 ----------------------
                                                 James Chao - President

                                      DATE:             1/24/92
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