Westlake Corporation (NYSE: WLK) (“Westlake”) announced today that it has completed the acquisition of the global compounding solutions businesses of the ACI/Perplastic Group (collectively, “ACI”). Headquartered in Portugal, ACI is a global manufacturer of specialty materials, primarily serving the wire and cable sectors. “The integration of ACI with Westlake’s compounding operations represents a strong strategic alignment, offering significant opportunities to further strengthen our Housing & Infrastructure Products (HIP) business. This acquisition will enhance the reach of Westlake Global Compounds and introduce new specialty products and advanced technologies to our portfolio,” stated Jean-Marc Gilson, President and Chief Executive Officer of Westlake. “ACI has built an impressive reputation for delivering innovative, high-value solutions,” said Maribel Wilson, Vice President of Westlake Global Compounds. “We are excited to welcome their skilled team to Westlake and look

Westlake Corporation (NYSE: WLK) (“Westlake”) (the “Company”) announced today that the Company has approved a plan to cease operation of certain of the Company’s North American chlorovinyl production facilities, including: its polyvinyl chloride (“PVC”) plant at the Aberdeen, Mississippi site, which has an annual capacity of approximately 1 billion pounds of suspension PVC resin; its vinyl chloride monomer (“VCM”) plant at the Lake Charles, Louisiana North site, which has an annual capacity of approximately 910 million pounds of VCM; and one of its diaphragm chlor-alkali units at the Lake Charles, Louisiana South site, which has an annual capacity of approximately 825 million pounds of chlorine and 910 million pounds of caustic soda. The Company plans to continue supplying customers with PVC, VCM and chlor-alkali products from its seven other North American chlorovinyl facilities. Following the closures, the Company expects to have aggregate annual production capacity of approximately