Westlake Corporation (NYSE: WLK) (the "Company" or "Westlake") today announced third quarter 2025 results. SUMMARY FINANCIAL HIGHLIGHTS (in millions of dollars, except per share data and percentages) Three Months Ended September 30, 2025 Three Months Ended June 30, 2025 Three Months Ended September 30, 2024 Westlake Corporation Net sales $ 2,838 $ 2,953 $ 3,117 Income (loss) from operations $ (766 ) $ (109 ) $ 180 Net income (loss) attributable to Westlake Corporation $ (782 ) $ (142 ) $ 108 Diluted earnings (loss) per common share $ (6.06 ) $ (1.11 )

Westlake Chemical Partners LP (NYSE: WLKP) (the “Partnership”) announced that Westlake Chemical OpCo LP (“OpCo”) and Westlake Corporation (“Westlake”) agreed to renew the Ethylene Sales Agreement between the parties through December 31, 2027 in accordance with its terms, which provides for an initial term through December 31, 2026 and automatic 12-month renewal periods until terminated at the end of the initial term or any renewal term on not less than 12-months’ notice. The renewal of the Ethylene Sales Agreement will facilitate continued offtake on attractive terms for 95% of the ethylene produced by OpCo. The renewed agreement maintains the same pricing formula and sales volume protections that have provided the Partnership with the distributable cash flow to make 45 consecutive quarterly distributions to unitholders, without any decreases, since its initial public offering in 2014. In connection with the renewal of the Ethylene Sales Agreement, OpCo and certain affiliates of

$0.4714 per unit distribution declared payable on November 26, 2025 The Board of Directors of Westlake Chemical Partners GP LLC, the general partner of Westlake Chemical Partners LP (the "Partnership") (NYSE:WLKP), has declared a distribution of $0.4714 per unit. This is the 45th quarterly distribution announced by the Partnership since its initial public offering. The distribution will be payable on November 26, 2025, to unit holders of record on November 10, 2025. This release is intended to be a qualified notice under Treasury Regulation Section 1.1446-4(b). Brokers and nominees should treat one hundred percent (100.0%) of the Partnership’s distributions to non-U.S. investors as being attributable to income that is effectively connected with a United States trade or business. Accordingly, the Partnership’s distributions to non-U.S. investors are subject to federal income tax withholding at the highest applicable effective tax rate. About Westlake Chemical Partners LP Westlake

Westlake Chemical Partners (NYSE: WLKP) will release its third quarter 2025 earnings prior to the market opening on Thursday, October 30, 2025. The company will host a conference call at 1:00 p.m. Eastern Time (12:00 p.m. Central Time) on the same day to discuss the earnings release. To access the conference by phone, it is necessary to pre-register at https://register-conf.media-server.com/register/BI18a27e98796e4538920bcc251d12d94a . Once registered, you will receive a phone number and unique PIN number. When you dial in, you will input the PIN number to be placed into the call. The conference call and replay will be available via webcast at https://edge.media-server.com/mmc/p/zo2bvgiu and the earnings release can be obtained via the company's Web page at, https://investors.wlkpartners.com/corporate-profile/default.aspx . About Westlake Chemical Partners: Westlake Chemical Partners is a limited partnership formed by Westlake Corporation to operate, acquire and develop ethylene

Westlake Corporation (NYSE: WLK) will release its third quarter 2025 earnings prior to the market opening on Thursday, October 30, 2025. The company will host a conference call at 11:00 a.m. Eastern Time (10:00 a.m. Central Time) on the same day to discuss the earnings release. To access the conference by phone, it is necessary to pre-register at https://register-conf.media-server.com/register/BI407a290bfbf04abdbdcf5bdeb7f15366 . Once registered, you will receive a phone number and unique PIN number. When you dial in, you will input the PIN number to be placed into the call. The conference call and replay will be available via webcast at https://edge.media-server.com/mmc/p/eex75wdd and the earnings release can be obtained via the company’s Web page at https://investors.westlake.com/news/default.aspx . About Westlake: Westlake is a global manufacturer and supplier of materials and innovative products that enhance life every day. Headquartered in Houston, with operations in Asia, Europe