Summary of WESTLAKE CHEMICAL CORP

Item 5.02 Departure of Directors or Certain Officers; Election of Directors;
Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

(e)

On May 15, 2009, the Compensation Committee of the Board of Directors of Westlake Chemical Corporation (the "Company") adopted the Westlake Chemical Corporation Annual Incentive Plan (the "Incentive Plan"). The Incentive Plan is designed to conform to the provisions of the Company's 2004 Omnibus Incentive Plan. The Company's executive officers and other key employees are eligible to receive cash awards under the Incentive Plan. The Compensation Committee will administer the Incentive Plan with respect to the Company's executive officers, and the Company's Chief Executive Officer (or any other executive officer to whom the Chief Executive Officer may delegate such authority) will administer the Incentive Plan with respect to other participants. Awards under the Incentive Plan are intended to qualify as "qualified performance awards" under the Company's 2004 Omnibus Incentive Plan that comply with the rules applicable to performance-based compensation pursuant to Section 162(m) of the Internal Revenue Code.

Any bonuses paid under the Incentive Plan will be paid from an "Incentive Pool," and the amount of the Incentive Pool will be equal to the sum of the value of the target bonuses for all participants under the Incentive Plan.

The payment of bonuses from the Incentive Pool will not be authorized under the Incentive Plan unless one of the following performance goals for the performance period from January 1, 2009 to December 31, 2009 is satisfied:

Х the Company's total shareholder return for 2009 is within the top two-thirds relative to the Company's peer group,

Х the Company's EBITDA for 2009 is greater than the Company's EBITDA for 2008, or

Х the Company achieves an amount of cost reduction during 2009 that is at least 50% (or, under specified market circumstances, 30%) of an amount of cost reduction targeted by the Company at the beginning of 2009.

If the Incentive Pool is authorized, the Compensation Committee, or the Chief Executive Officer, with respect to participants who are not executive officers, may reduce (but not increase) the Incentive Pool by reducing the size of a participant's target bonus to reflect additional quantitative and qualitative factors, including total shareholder return, safety, cost reductions, amounts payable under EVA (economic value added) Incentive Plan (EVAIP) and individual performance factors. The Company expects that the awards for 2009 will be determined and paid in the first quarter of 2010. The aggregate of target bonuses under the Incentive Plan and the EVAIP for each of the Company's named executive officers shall not exceed the target bonuses for the EVAIP set forth as a percentage of base pay under "Compensation Discussion and Analysis-Cash Incentive Plans/Bonuses" in the Company's proxy statement related to its 2009 annual meeting.

The foregoing description of the Incentive Plan is qualified in its entirety by reference to the complete document, which is filed as Exhibit 10.1 to this Current Report on Form 8-K and incorporated herein by reference.