EXHIBIT 3.63


                       CERTIFICATE OF LIMITED PARTNERSHIP

         The undersigned, desiring to form a limited partnership pursuant to the
Delaware Revised Uniform Limited Partnership Act, 6 Delaware Code, Chapter 17,
do hereby certify as follows:

         I. The name of the limited partnership is WPT LP.

         II. The address of the Partnership's registered office in the State of
Delaware is 103 Foulk Road, Suite 200, Wilmington, DE 19803. The registered
agent for service of process in the State of Delaware at such address is Entity
Services Group, L.L.C.

         III. The name and mailing address of each general partner is as
follows:

<Table>
<Caption>
                      NAME                          MAILING ADDRESS
                      ----                          ---------------
                                           
          Westlake Chemical Holdings, Inc.    2801 Post Oak Boulevard, Suite 600
                                              Houston, TX  77056
</Table>


         IN WITNESS WHEREOF, the undersigned has executed this Certificate of
Limited Partnership of WPT LP as of December 20, 2000.

                                         WESTLAKE CHEMICAL HOLDINGS, INC.,
                                         GENERAL PARTNER

                                         By: /s/ A. Chao
                                             ---------------------------------
                                             Albert Chao, President