North American Pipe to Open New PVC Pipe Plant

                     Facility to be located in Yucca, AZ

HOUSTON, March 19 /PRNewswire-FirstCall/ -- North American Pipe Corporation, a subsidiary of Houston-based Westlake Chemical Corporation (NYSE: WLK), announced today that it will open a new PVC pipe plant in Yucca, AZ.

The new plant is expected to begin operations by the 1st quarter of 2009 and will annually produce approximately 120 million pounds of PVC pipe in its initial phase. With an initial investment of approximately $30 million the plant will add approximately 75 new positions to the local economy.

The facility will produce PVC pipe for the water, sewer, irrigation and related industrial and residential markets in diameters ranging from 2 to 36 inches. When this plant is completed, the company's annual PVC pipe capacity will be increased to approximately 985 million pounds.

Mr. Mike Powell, North American Pipe's Vice President and General Manager stated, "This new pipe plant is an important part of our integrated vinyls strategy and will allow us to serve our pipe customers from coast-to-coast with a wide array of pipe solutions."

North American Pipe Corporation

North American Pipe is a wholly-owned subsidiary of Westlake Chemical Corporation and currently operates eight (8) PVC pipe plants throughout the United States. Last fall the company announced it was beginning construction of a PVC pipe plant in Calvert City, KY with a capacity of 55 million pounds per year of large diameter pipe which is expected to be completed in the second half of 2008. For more information, visit http://www.northamericanpipe.com.

Westlake Chemical Corporation (WLK)

Westlake Chemical Corporation is a manufacturer and supplier of petrochemicals, polymers and fabricated products with headquarters in Houston, Texas. The company's range of products includes: ethylene, polyethylene, styrene, propylene, caustic, VCM, PVC and PVC pipe, windows and fence. For more information, visit the company's Web site at http://www.westlake.com.

The statements in this release relating to the new pipe plant, as well as any other matters that are not historical facts, are forward-looking statements that are subject to risks and uncertainties. Actual results could differ materially. For more detailed information about factors that could cause actual results to differ materially, please refer to Westlake's Annual Report on Form 10-K for the year ended December 31, 2007, which was filed in February 2008.