Jean-Marc Gilson, Experienced Chemicals Industry Executive, Appointed President and CEO Albert Chao and James Chao to Remain Actively Engaged as Executive Chairman and Senior Chairman of the Board, Respectively Westlake Corporation (NYSE: WLK) (the “Company” or “Westlake”) today announced that Jean-Marc Gilson, who most recently served as President and Chief Executive Officer of Mitsubishi Chemical Group Corporation, has been appointed by the Board of Directors to serve as President and Chief Executive Officer of Westlake. Jean-Marc Gilson succeeds Albert Chao, who will transition to become Executive Chairman of the Westlake Board of Directors. James Chao, the current Chairman of the Board, will become Senior Chairman of the Westlake Board of Directors. These appointments take effect today. This press release features multimedia. View the full release here: https://www.businesswire.com/news/home/20240715230107/en/ Jean-Marc Gilson, new President and Chief Executive Officer of Westlake

Westlake Vinnolit won the PVC category of the 2024 ‘Polymer Producer Awards’ by the Polymers for Europe Alliance (PEA), applying PEA criteria focused on delivery reliability, circularity, quality, communication, innovation and commitment to the European Market. Westlake Vinnolit also won PEA's ‘Overall Award – Decarbonization’, in recognition of the company's achievements in the field of CO2-saving PVC resins. This year, a particularly large number of plastics converters took part in the annual polymer producers’ assessment sponsored by the Polymers for Europe Alliance . All polymers users in Europe had until mid-May to vote and rate their polymer suppliers' performance during the past 12 months. Following this year's key criteria delivery reliability, circularity, quality, communication, innovation and commitment to the European Market, Westlake Vinnolit won the PVC category with 92% of the vote. "We are delighted with this great success and would like to thank our customers for

Net income of $394 million increased 70% from fourth quarter 2022 Westlake Corporation (NYSE: WLK) (the "Company" or "Westlake") today announced first quarter 2023 results. SUMMARY FINANCIAL HIGHLIGHTS ($ in millions except per share data)     Three Months Ended March 31, 2023   Three Months Ended December 31, 2022   Three Months Ended March 31, 2022                     Westlake Corporation                   Net sales   $ 3,356     $ 3,299     $ 4,056   Income from operations   $ 536     $ 327     $ 1,032   Operating income margin     16%       10%       25%   Net income attributable to Westlake Corporation   $ 394    

Housing and Infrastructure Products segment provided earnings stability Cash from operations of $555 million and free cash flow of $315 million Westlake Corporation (NYSE: WLK) (the "Company" or "Westlake") today announced second quarter 2023 results. SUMMARY FINANCIAL HIGHLIGHTS ($ in millions except per share data)     Three Months Ended June 30, 2023   Three Months Ended March 31, 2023   Three Months Ended June 30, 2022                     Westlake Corporation                   Net sales   $ 3,251     $ 3,356     $ 4,483   Income from operations   $ 396     $ 536     $ 1,175   Operating income margin     12%       16%       26%   Net income attributable to Westlake Corporation   $ 297

Record Housing and Infrastructure Products segment income from operations of $256 million Record Housing and Infrastructure Products segment EBITDA of $327 million Net cash provided by operating activities of $696 million and free cash flow of $451 million Westlake Corporation (NYSE: WLK) (the "Company" or "Westlake") today announced third quarter 2023 results. SUMMARY FINANCIAL HIGHLIGHTS ($ in millions except per share data)       Three Months Ended September 30, 2023   Three Months Ended June 30, 2023   Three Months Ended September 30, 2022               Westlake Corporation             Net sales   $ 3,115     $ 3,251     $ 3,956   Income from operations   $ 349     $ 396     $ 516   Operating income margin     11%     12%     13%

Record Housing and Infrastructure Products (HIP) annual income from operations of $710 million with a 17% income from operations margin and a 23% EBITDA margin Generated $2.3 billion of net cash from operating activities and $1.3 billion of free cash flow in 2023 Performance and Essential Materials (PEM) results impacted by Identified Items totaling $625 million Westlake Corporation (NYSE: WLK) (the "Company" or "Westlake") today announced fourth quarter and full year 2023 results. SUMMARY FINANCIAL HIGHLIGHTS ($ in millions except per share data and percentages)       Three Months Ended   Twelve Months Ended     December 31,   September 30,   December 31,   December 31,     2023   2023   2022   2023   2022 Westlake Corporation                     Net sales   $ 2,826     $ 3,115     $ 3,299     $ 12,548     $ 15,794

Record first quarter Housing and Infrastructure Products (HIP) income from operations of $210 million with a 20% operating income margin HIP EBITDA of $264 million rose 29% year-over-year with a record first quarter EBITDA margin of 25% PEM sales volume grew 3% sequentially from gradual demand recovery with stable average sales prices Westlake Corporation (NYSE: WLK) (the "Company" or "Westlake") today announced first quarter 2024 results. SUMMARY FINANCIAL HIGHLIGHTS (in millions of dollars, except per share data and percentages)       Three Months Ended March 31, 2024   Three Months Ended December 31, 2023   Three Months Ended March 31, 2023 Westlake Corporation             Net sales   $ 2,975     $ 2,826     $ 3,356   Income (loss) from operations   $ 223     $ (552 )   $ 536   Net income (loss) attributable to Westlake Corporation   $ 174     $ (497 )  

Westlake Corporation (NYSE: WLK) today announced that Westlake Epoxy’s European business has been awarded a 2024 Gold Medal from EcoVadis. This award positions Westlake Epoxy among the top 5% of businesses in the chemical industry receiving this esteemed recognition from EcoVadis. EcoVadis is the world’s largest and most trusted provider of business sustainability ratings and evaluates companies globally on their corporate social responsibility (CSR) performance using international standards like the Global Reporting Initiative, the United Nations Global Compact, and ISO 26000. In attaining Gold Medal status, EcoVadis recognized the Westlake Epoxy business in Europe as advanced performing in the assessed fields of Environment, Labor & Human Rights, Ethics and Sustainable Procurement. Across all categories, Westlake Epoxy attained a total score of 75 out of 100 points in 2024, ranking it in the top 97th percentile of businesses in the chemical industry (“basic chemicals,

Updates Full-Year 2024 Outlook for Housing and Infrastructure Products Westlake Corporation (NYSE: WLK) will host a teach-in today focused on its Housing and Infrastructure Products (“HIP”) businesses beginning at 9:00 AM Eastern Time. The event will include formal presentations and a Q&A panel session with senior leadership and is expected to conclude around 1:00 PM Eastern Time. During the event, Albert Chao, President and Chief Executive Officer; Steve Bender, Executive Vice President and Chief Financial Officer; Robert Buesinger, Executive Vice President – Housing & Infrastructure Products, IT & Digital; and the leaders of Westlake Royal Building Products, Westlake Pipe & Fittings, and Westlake Global Compounds, will present an in-depth overview of the Company's HIP segment, including: The positive long-term demand fundamentals driving growth across the business segments The diverse end markets served by each business segment through strong brands, innovative