HOUSTON, Sept. 9 /PRNewswire-FirstCall/ -- Westlake Chemical Corporation (NYSE: WLK) announced today that the underwriters of its recent initial public offering of common stock have exercised their over-allotment option to purchase an additional 1,626,506 shares of common stock from the company at a price of $14.50 per share.

Credit Suisse First Boston, JPMorgan and Deutsche Bank Securities acted as co-managers of the offering.

Westlake Chemical Corporation is an international manufacturer and supplier of petrochemicals, polymers and fabricated products with headquarters in Houston, Texas. The company's range of products includes ethylene, polyethylene, styrene, vinyl intermediates, PVC, PVC pipe, PVC windows, fence and decking components. More information on the company can be found at http://www.westlakechemical.com .

This press release shall not constitute an offer to sell or the solicitation of an offer to buy any securities of Westlake Chemical, nor shall there be any sales of any such securities in any state or other jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or other jurisdiction.

Copies of the prospectus relating to the offering may be obtained by writing to or telephoning the underwriters: Credit Suisse First Boston LLC, Prospectus Department, One Madison Avenue, New York, NY 10010, tel. 212-325-2580; J.P. Morgan Securities Inc., Prospectus Department, One Chase Manhattan Plaza, Floor 5B, New York, NY 10081, tel. 212-552-5164; or Deutsche Bank Securities Inc, c/o Prospectus Department, 1251 Avenue of the Americas, 25th Floor, New York, NY 10020, tel. 212-474-8372.

SOURCE  Westlake Chemical Corporation
    -0-                             09/09/2004
    /CONTACT:  David R. Hansen, Media Relations,
dhansen@westlakechemical.com , or Graham McArthur, Investor Relations,
gmcarthur@westlakechemical.com , both of Westlake Chemical Corporation,
+1-713-960-9111/
    /Web site:  http://www.westlakechemical.com /
    (WLK)

CO:  Westlake Chemical Corporation; Credit Suisse First Boston LLC; J.P.
     Morgan Securities Inc.; Deutsche Bank Securities Inc.
ST:  Texas, New York
IN:  CHM FIN
SU:

AW-AP 
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4311 09/09/2004 18:00 EDT http://www.prnewswire.com