Westlake Corporation (NYSE: WLK) (“Westlake”) announced today that it has priced its previously announced underwritten public offering of $600,000,000 aggregate principal amount of senior unsecured notes due 2035 (the “2035 Notes”) and $600,000,000 aggregate principal amount of senior unsecured notes due 2055 (the “2055 Notes” and, together with the 2035 Notes, the “Notes”) under its existing shelf registration statement. The 2035 Notes will bear interest at a rate of 5.550% per annum and will mature on November 15, 2035. The 2055 Notes will bear interest at a rate of 6.375% per annum and will mature on November 15, 2055. The sale of the Notes is scheduled to close on November 6, 2025, subject to the satisfaction of customary closing conditions. Westlake intends to use the net proceeds from the proposed public offering of the Notes to fund the repurchase of its outstanding 3.600% Senior Notes due 2026 (the “2026 Senior Notes”) pursuant to a concurrent cash tender offer (the “Tender

Westlake Corporation (NYSE: WLK) (“Westlake”) announced today the commencement of a cash tender offer to purchase (the “Offer”) any and all of the outstanding 3.600% Senior Notes due 2026 (the “Notes”) as set forth in the table below. The tender offer is being made solely pursuant to the terms and conditions set forth in an Offer to Purchase, dated November 4, 2025 (the “Offer to Purchase”). Holders of the Notes are urged to carefully read the Offer to Purchase before making any decision with respect to the tender offer. The tender offer is not conditioned on any minimum amount of the Notes being tendered. Subject to applicable law, Westlake may amend, extend or terminate the tender offer in its sole discretion. Capitalized terms used but not defined in this announcement have the meanings given to them in the Offer to Purchase. Series of Notes CUSIP Numbers(1) Aggregate Principal Amount Outstanding U.S. Treasury Reference Security(2) Bloomberg Reference Page(2) Fixed Spread(3) 3.600%

Westlake Corporation (NYSE: WLK) (“Westlake”) announced today the commencement of an underwritten public offering, subject to market and other conditions, of senior unsecured notes (the “Notes”) under its existing shelf registration statement. The timing of pricing and terms of the Notes are subject to market conditions and other factors. Westlake intends to use the net proceeds from the proposed public offering of the Notes to fund the repurchase of its outstanding 3.600% Senior Notes due 2026 (the “2026 Senior Notes”) pursuant to a concurrent cash tender offer (the “Tender Offer”) for any and all of the 2026 Senior Notes. Westlake anticipates using any remaining net proceeds to fund the purchase price of its pending acquisition of the global compounding solutions businesses of the ACI/Perplastic Group (the “ACI Acquisition”) and for general corporate purposes, including working capital management. The offering of the Notes is not contingent upon the successful completion of the

Renewed Ethylene Sales Agreement through 2027 at existing terms Declared quarterly distribution of $0.4714 per unit; 45 th consecutive quarterly distribution Westlake Chemical Partners LP (NYSE: WLKP) (the "Partnership") today reported net income attributable to the Partnership in the third quarter of 2025 of $14.7 million, or $0.42 per limited partner unit, which was below third quarter 2024 net income of $18.1 million. Cash flows from operating activities in the third quarter of 2025 were $105.2 million, a decrease of $20.9 million compared to third quarter 2024 cash flows from operating activities of $126.1 million. For the three months ended September 30, 2025, MLP distributable cash flow was $14.9 million, a decrease of $3.0 million compared to third quarter 2024 MLP distributable cash flow of $17.9 million. The decrease in MLP distributable cash flow and associated trailing twelve-month coverage ratio was primarily due to higher maintenance capital expenditures. Third quarter

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