WESTLAKE CORP — Director's Dealing 2011

May 11, 2011

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: WESTLAKE CHEMICAL CORP (WLK)
CIK: 0001262823
Period of Report: 2011-05-10

Reporting Person: LUKENS MAX L (Director)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2011-05-10	Common Stock	M	1345	$30.07	Acquired	9570	Direct
2011-05-10	Common Stock	M	1440	$27.125	Acquired	11010	Direct
2011-05-10	Common Stock	M	1912	$20.825	Acquired	12922	Direct
2011-05-10	Common Stock	M	887	$24.51	Acquired	13809	Direct
2011-05-10	Common Stock	S	200	$60.69	Disposed	13609	Direct
2011-05-10	Common Stock	S	4000	$60.67	Disposed	9609	Direct
2011-05-10	Common Stock	S	400	$60.66	Disposed	9209	Direct
2011-05-10	Common Stock	S	500	$60.64	Disposed	8709	Direct
2011-05-10	Common Stock	S	184	$60.63	Disposed	8525	Direct
2011-05-10	Common Stock	S	300	$60.61	Disposed	8225	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2011-05-10	Employee Option (right to buy)	$30.07	A	1345	Acquired	2020-08-21	Common Stock (1345)	Direct
2011-05-10	Employee Option (right to buy) Common Stock	$27.125	A	1440	Acquired	2020-08-17	Common Stock (1440)	Direct
2011-05-10	Employee Option (right to buy) (Common Stock	$20.825	A	1912	Acquired	2020-08-15	Common Stock (1912)	Direct
2011-05-10	Employee Option (right to buy) (Common Stock)	$24.51	A	887	Acquired	2020-08-20	Common Stock (887)	Direct