Westlake Corporation Announces Results of Cash Tender Offer for Its 3.600% Senior Notes Due 2026

Westlake Corporation (NYSE: WLK) (“Westlake”) today announced the expiration and results of its cash tender offer to purchase (the “Offer”) any and all of the outstanding 3.600% Senior Notes due 2026 (the “Notes”). The tender offer described herein was made on the terms and subject to the conditions set forth in the Offer to Purchase, dated November 4, 2025 (the “Offer to Purchase”) and the related Notice of Guaranteed Delivery. Capitalized terms used but not defined in this announcement have the meanings given to them in the Offer to Purchase. The tender offer expired at 5:00 p.m., New York City time, on November 10, 2025 (the “Expiration Date”). The settlement date for the Offer will be on or about November 12, 2025 (the “Settlement Date”).

According to information provided by Global Bondholder Services Corporation, $253,730,000 aggregate principal amount of the Notes were validly tendered (other than pursuant to the guaranteed delivery procedures set forth in the Offer to Purchase (the “Guaranteed Delivery Procedures”)) prior to or at the Expiration Date and not validly withdrawn. In addition, $10,733,000 aggregate principal amount of the Notes were reflected in Notices of Guaranteed Delivery delivered at or prior to the Expiration Date and remain subject to the Holders’ performance of the delivery requirements under the Guaranteed Delivery Procedures. The table below provides certain information about the tender offer, including the aggregate principal amount of the Notes validly tendered and not validly withdrawn prior to the Expiration Date and the aggregate principal amount of Notes reflected in Notices of Guaranteed Delivery delivered at or prior to the Expiration Date.

Westlake intends to accept for purchase $253,730,000 aggregate principal amount of Notes under the tender offer (excluding Notes delivered pursuant to the Guaranteed Delivery Procedures).

Series of Notes	CUSIP Numbers (1)	Aggregate Principal Amount Outstanding	Aggregate Principal Amount Tendered(2)	Principal Amount Reflected in Notices of Guaranteed Delivery
3.600% Senior Notes due 2026	960413AT9 (Registered) 960413AH5 (Rule 144A) U96060AC9 (Reg. S)	$750,000,000