WESTLAKE CORP — Director's Dealing 2012

May 31, 2012

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: WESTLAKE CHEMICAL CORP (WLK)
CIK: 0001262823
Period of Report: 2012-05-29

Reporting Person: Chao James (Director, Chairman, 10% Owner, 10% Owner)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2012-05-29	Common Stock	M	70194	$14.235	Acquired	161102	Direct
2012-05-29	Common Stock	S	4957	$56.74	Disposed	156145	Direct
2012-05-29	Common Stock	S	1400	$56.75	Disposed	154745	Direct
2012-05-29	Common Stock	S	1000	$56.76	Disposed	153745	Direct
2012-05-29	Common Stock	S	3800	$56.78	Disposed	149945	Direct
2012-05-29	Common Stock	S	8300	$56.79	Disposed	141645	Direct
2012-05-29	Common Stock	S	5849	$56.80	Disposed	135796	Direct
2012-05-29	Common Stock	S	3139	$56.81	Disposed	132657	Direct
2012-05-29	Common Stock	S	1000	$56.82	Disposed	131657	Direct
2012-05-29	Common Stock	S	903	$56.83	Disposed	130754	Direct
2012-05-29	Common Stock	S	100	$56.832	Disposed	130654	Direct
2012-05-29	Common Stock	S	462	$56.84	Disposed	130192	Direct
2012-05-29	Common Stock	S	200	$56.8401	Disposed	129992	Direct
2012-05-29	Common Stock	S	300	$56.85	Disposed	129692	Direct
2012-05-29	Common Stock	S	366	$56.86	Disposed	129326	Direct
2012-05-29	Common Stock	S	2079	$56.87	Disposed	127247	Direct
2012-05-29	Common Stock	S	600	$56.8725	Disposed	126647	Direct
2012-05-29	Common Stock	S	399	$56.88	Disposed	126248	Direct
2012-05-29	Common Stock	S	204	$56.90	Disposed	126044	Direct
2012-05-29	Common Stock	S	20	$56.91	Disposed	126024	Direct
2012-05-29	Common Stock	S	2646	$56.92	Disposed	123378	Direct
2012-05-29	Common Stock	S	100	$56.925	Disposed	123278	Direct
2012-05-29	Common Stock	S	1120	$56.93	Disposed	122158	Direct
2012-05-29	Common Stock	S	100	$56.94	Disposed	122058	Direct
2012-05-29	Common Stock	S	498	$56.95	Disposed	121560	Direct
2012-05-29	Common Stock	S	3540	$56.96	Disposed	118020	Direct
2012-05-29	Common Stock	S	2178	$56.97	Disposed	115842	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2012-05-29	Employee Option (right to buy)	$14.235	M	70194	Acquired	2019-02-13	Common Stock (70194)	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	20000	Indirect
Common Stock	120875	Indirect
Common Stock	46005277	Indirect

Footnotes

F1: Even though reporting person and reporting person's mother share a household, the reporting person disclaims beneficial ownership of these securities, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities for purposes of Section 16 or for any other purpose.

F2: Even though reporting person and reporting person's brother, Albert Chao, share a household, the reporting person disclaims beneficial ownership of these securities, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities for purposes of Section 16 or for any other purpose.