WESTLAKE CORP — Director's Dealing 2011

May 9, 2011

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: WESTLAKE CHEMICAL CORP (WLK)
CIK: 0001262823
Period of Report: 2011-05-06

Reporting Person: Mangieri George J (VP & Chief Accounting Officer)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2011-05-06	Common Stock	M	5128	$14.235	Acquired	30883	Direct
2011-05-06	Common Stock	M	2307	$20.525	Acquired	33190	Direct
2011-05-06	Common Stock	S	7035	$60.262	Disposed	26155	Direct
2011-05-06	Common Stock	S	400	$60.36	Disposed	25755	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2011-05-06	Employee Option (right to buy)	$14.235	A	5128	Acquired	2019-02-13	Common Stock (5128)	Direct
2011-05-06	Employee Option (right to buy) (Common Stock)	$20.525	A	2307	Acquired	2020-02-26	Common Stock (2307)	Direct