1 unchanged sentence
Rule 10b5-1 Trading Arrangements.
−Removed: During the three months ended June 30, 2025, no director or officer of the Partnership's general partner adopted or terminated a "Rule 10b5-1 trading arrangement" or "non-Rule 10b5-1 trading arrangement," as each term is defined in Item 408 of Regulation S-K.
+Added: During the three months ended September 30, 2025 , no director or officer of the Partnership's general partner adopted or terminated a "Rule 10b5-1 trading arrangement" or "non-Rule 10b5-1 trading arrangement," as each term is defined in Item 408 of Regulation S-K.
3.1 Certificate of Limited Partnership of Westlake Chemical Partners LP (incorporated by reference to Exhibit 3.1 to Westlake Chemical Partners LP's Registration Statement on Form S-1 (File No.
12 unchanged sentences
01-36567) filed on March 1, 2018).
+Added: 10.1 First Amendment to Services and Secondment Agreement by and among Westlake Chemical OpCo LP, Westlake Management Services, Inc., Westlake Vinyls, Inc., WPT LLC and Westlake Petrochemicals LLC (incorporated by Reference to Exhibit 10.2 to Westlake Chemical Partners LP's Current Report on Form 8-K, filed on October 30, 2025, File No.
+Added: 10.2 First Amendment to the Omnibus Agreement among Westlake Management Services, Inc., Westlake Vinyl Corporation, Westlake Chemical Partners GP LLC, Westlake Chemical Partners LP, WPT LLC, Westlake Petrochemicals LLC, Westlake Vinyls, Inc., Westlake Longview Corporation, Westlake Chemical OpCo GP LLC, Westlake Chemical OpCo LP, Westlake PVC Corporation, Westlake Styrene LLC and Westlake Polymers LLC (incorporated by Reference to Exhibit 10.4 to Westlake Chemical Partners LP's Current Report on Form 8-K, filed on October 30, 2025, File No.
31.1† Rule 13a – 14(a) / 15d – 14(a) Certification (Principal Executive Officer)
13 unchanged sentences
WESTLAKE CHEMICAL PARTNERS LP
−Removed: August 6, 2025 By:
+Added: October 31, 2025 By:
/ S / J EAN -M ARC G ILSON
3 unchanged sentences
(Principal Executive Officer)
−Removed: August 6, 2025 By:
+Added: October 31, 2025 By:
S TEVEN B ENDER
4 unchanged sentences
Compared sentence by sentence after normalising whitespace, quotation marks, case and digits, so re-formatting and restated figures do not read as changed language. Wording changes appear as one removal and one addition. The current filing and the prior one are authoritative.