X0306 4 2017-08-30 0 0001604665 Westlake Chemical Partners LP WLKP 0001262852 WPT LLC 2801 POST OAK BLVD SUITE 600 HOUSTON TX 77056 0 0 1 0 0001262823 WESTLAKE CHEMICAL CORP 2801 POST OAK BLVD SUITE 600 HOUSTON TX 77056 0 0 1 0 0001262845 WESTLAKE POLYMERS LLC 2801 POST OAK BLVD SUITE 600 HOUSTON TX 77056 0 0 1 0 0001262834 WESTLAKE CHEMICAL INVESTMENTS, INC. 2801 POST OAK BLVD SUITE 600 HOUSTON TX 77056 0 0 1 0 0001262842 WESTLAKE OLEFINS CORP 2801 POST OAK BLVD SUITE 600 HOUSTON TX 77056 0 0 1 0 0001299601 TTWF LP 2801 POST OAK BLVD SUITE 600 HOUSTON TX 77056 0 0 1 0 0001299599 TTWFGP LLC 2801 POST OAK BLVD SUITE 600 HOUSTON TX 77056 0 0 1 0 Common Units (Limited Partner Interests) 2017-08-30 4 C 0 12686115 A 14122230 D Subordinated Units (Limited Partner Interests) 2017-08-30 4 C 0 12686115 D Common Units (Limited Partner Interests) 12686115 0 D On August 30, 2017, pursuant to the terms of the agreement of limited partnership (the "Partnership Agreement") of the Issuer, the 12,686,115 subordinated units representing limited partner interests in the Issuer (the "subordinated units") acquired by WPT LLC ("WPT") in the Issuer's initial public offering converted into common units representing limited partner interests of the Issuer ("common units") on a one-for-one basis, resulting in the acquisition of 12,686,115 common units. The subordinated units had no expiration date. As of August 30, 2017, (i) WPT owns 55.7% of the outstanding limited partner interests in the Issuer. Westlake Chemical Corporation ("Westlake") owns 100% of Westlake Olefins Corporation, which owns 100% of Westlake Chemical Investments, Inc., which owns 100% of Westlake Polymers LLC, which owns 100% of WPT. TTWF LP, a Delaware limited partnership, holds 92,010,554 shares of Westlake's common stock. TTWF GP LLC, a Delaware limited liability company, is the general partner of TTWF LP. Each of the reporting persons in the above described ownership chain of WPT may be deemed to indirectly own the common units and the subordinated units directly held by WPT. WPT LLC, /s/ Albert Chao, by Albert Chao President of Westlake Chemical Investments, Inc. its manager 2017-08-30 Westlake Polymers LLC, /s/ Albert Chao, by Albert Chao, President of Westlake Chemical Investments, Inc., its manager 2017-08-30 Westlake Chemical Investments, Inc., /s/ Albert Chao, by Albert Chao, President 2017-08-30 Westlake Olefins Corporation, /s/ Albert Chao, by Albert Chao, President 2017-08-30 TTWF LP, by TTWF GP LLC, its general partner, /s/ Albert Chao, by Albert Chao, an Authorized Representative, /s/ James Chao, James Chao, an Authorized Representative 2017-08-30 TTWF GP LLC, /s/ Albert Chao, By: Albert Chao, an Authorized Representative, /s/ James Chao, James Chao, an Authorized Representative 2017-08-30 Westlake Chemical Corporation, /s/ Albert Chao, by Albert Chao, President and CEO 2017-08-30