Westlake Chemical Partners LP 10-Q

Item 1. Financial Statements WESTLAKE CHEMICAL PARTNERS LP CONSOLIDATED BALANCE SHEETS (Unaudited) March 31, 2026 December 31, 2025 (in thousands of dollars, except unit amounts) ASSETS Current assets Cash and cash equivalents $ 44,290 $ 44,269 Receivable under the Investment Management Agreement—Westlake Corporation ("Westlake") 36,441 23,378 Accounts receivable, net—Westlake 45,082 63,571 Accounts receivable, net—third parties 19,778 9,113 Inventories 3,093 2,769 Prepaid expenses and other current assets 219 406 Total current assets 148,903 143,506 Property, plant and equipment, net 871,606 886,012 Goodwill 5,814 5,814 Deferred charges and other assets, net 209,375 221,201 Total assets $ 1,235,698 $ 1,256,533 LIABILITIES Current liabilities Accounts payable—Westlake $ 8,706 $ 19,132 Accounts payable—third parties 10,239 9,970 Accrued and other liabilities 21,847 22,199 Total current liabilities 40,792 51,301 Long-term debt payable to Westlake 399,674 399,674 Deferred income taxes 1,520 1,546 Other liabilities 1,326 1,660 Total liabilities 443,312 454,181 Commitments and contingencies (Note 12) EQUITY Common unitholders—publicly and privately held ( 21,123,649 and 21,123,649 units issued and outstanding at March 31, 2026 and December 31, 2025, respectively) 459,382 460,848 Common unitholder—Westlake ( 14,122,230 and 14,122,230 units issued and outstanding at March 31, 2026 and December 31, 2025, respectively) 39,280 40,260 General partner—Westlake ( 242,572 ) ( 242,572 ) Total Westlake Chemical Partners LP partners' capital 256,090 258,536 Noncontrolling interest in Westlake Chemical OpCo LP ("OpCo") 536,296 543,816 Total equity 792,386 802,352 Total liabilities and equity $ 1,235,698 $ 1,256,533 The accompanying notes are an integral part of the consolidated financial statements. 1 Table of Contents WESTLAKE CHEMICAL PARTNERS LP CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) Three Months Ended March 31, 2026 2025 (in thousands of dollars, except unit amounts and per unit data) Revenue Net sales—Westlake $ 263,091 $ 190,781 Net co-products, ethylene and other sales—third parties 42,584 46,848 Total net sales 305,675 237,629 Cost of sales 211,916 183,548 Gross profit 93,759 54,081 Selling, general and administrative expenses 7,190 7,474 Income from operations 86,569 46,607 Other income (expense) Interest expense—Westlake ( 5,085 ) ( 5,537 ) Other income, net 348 1,346 Income before income taxes 81,832 42,416 Provision for income taxes 177 107 Net income 81,655 42,309 Less: Net income attributable to noncontrolling interest in OpCo 67,486 37,361 Net income attributable to Westlake Chemical Partners LP and limited partners' interest in net income $ 14,169 $ 4,948 Net income per limited partner unit attributable to Westlake Chemical Partners LP (basic and diluted) Common units $ 0.40 $ 0.14 Weighted average limited partner units outstanding (basic and diluted) Common units—publicly and privately held 21,123,649 21,116,326 Common units—Westlake 14,122,230 14,122,230 The accompanying notes are an integral part of the consolidated financial statements. 2 Table of Contents WESTLAKE CHEMICAL PARTNERS LP CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Unaudited) Partnership Common Unitholders — Publicly and Privately Held Common Unitholder — Westlake General Partner — Westlake Noncontrolling Interest in OpCo Total (in thousands of dollars) Balances at December 31, 2025 $ 460,848 $ 40,260 $ ( 242,572 ) $ 543,816 $ 802,352 Net income 8,492 5,677 — 67,486 81,655 Distribution to unitholders ( 9,958 ) ( 6,657 ) — — ( 16,615 ) Distribution to noncontrolling interest retained in OpCo by Westlake — — — ( 75,006 ) ( 75,006 ) Balances at March 31, 2026 $ 459,382 $ 39,280 $ ( 242,572 ) $ 536,296 $ 792,386 The accompanying notes are an integral part of the consolidated financial statements. 3 Table of Contents WESTLAKE CHEMICAL PARTNERS LP CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Unaudited) Partnership Common Unitholders— Publicly and Privately Held Common Unitholder— Westlake General Partner— Westlake Noncontrolling Interest in OpCo Total (in thousands of dollars) Balances at December 31, 2024 $ 471,328 $ 47,373 $ ( 242,572 ) $ 553,185 $ 829,314 Net income 2,965 1,983 — 37,361 42,309 Distribution to unitholders ( 9,954 ) ( 6,657 ) — — ( 16,611 ) Distribution to noncontrolling interest retained in OpCo by Westlake — — — ( 51,906 ) ( 51,906 ) Balances at March 31, 2025 $ 464,339 $ 42,699 $ ( 242,572 ) $ 538,640 $ 803,106 The accompanying notes are an integral part of the consolidated financial statements. 4 Table of Contents WESTLAKE CHEMICAL PARTNERS LP CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) Three Months Ended March 31, 2026 2025 (in thousands of dollars) Cash flows from operating activities Net income $ 81,655 $ 42,309 Adjustments to reconcile net income to net cash provided by operating activities Depreciation and amortization 34,299 27,068 Loss from disposition of property, plant and equipment 61 103 Other losses, net 70 137 Changes in operating assets and liabilities Accounts receivable—third parties ( 10,761 ) ( 1,553 ) Net accounts receivable—Westlake 8,000 ( 1,164 ) Inventories ( 324 ) 1,325 Prepaid expenses and other current assets 187 243 Accounts payable—third parties ( 290 ) 36,942 Accrued and other liabilities ( 2,208 ) 45,892 Deferred charges and other assets and others, net ( 491 ) ( 105,521 ) Net cash provided by operating activities 110,198 45,781 Cash flows from investing activities Additions to property, plant and equipment ( 5,556 ) ( 15,956 ) Investments with Westlake under the Investment Management Agreement ( 13,000 ) — Maturities of investments with Westlake under the Investment Management Agreement — 30,000 Net cash provided by (used for) investing activities ( 18,556 ) 14,044 Cash flows from financing activities Proceeds from debt payable to Westlake 40,500 54,000 Repayment of debt payable to Westlake ( 40,500 ) ( 54,000 ) Distributions to noncontrolling interest retained in OpCo by Westlake ( 75,006 ) ( 51,906 ) Distributions to unitholders ( 16,615 ) ( 16,611 ) Net cash used for financing activities ( 91,621 ) ( 68,517 ) Net increase (decrease) in cash and cash equivalents 21 ( 8,692 ) Cash and cash equivalents at beginning of period 44,269 58,316 Cash and cash equivalents at end of period $ 44,290 $ 49,624 The accompanying notes are an integral part of the consolidated financial statements. 5 Table of Contents WESTLAKE CHEMICAL PARTNERS LP NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — Continued (Unaudited) (in thousands of dollars, except unit amounts and per unit data) 1. Description of Business and Basis of Presentation Description of Business Westlake Chemical Partners LP (the "Partnership") is a Delaware limited partnership formed in March 2014 to operate, acquire and develop ethylene production facilities and related assets. On August 4, 2014, the Partnership completed its initial public offering (the "IPO") of 12,937,500 common units representing limited partner interests. The Partnership owns a 22.8 % limited partner interest in Westlake Chemical OpCo LP ("OpCo") and a 100 % interest in Westlake Chemical OpCo GP LLC ("OpCo GP"), which is the general partner of OpCo. OpCo owns three ethylene production facilities and one common carrier ethylene pipeline. The remaining 77.2 % limited partner interest in OpCo is owned by Westlake Corporation. References to "Westlake" refer collectively to Westlake Corporation and its subsidiaries, other than the Partnership, OpCo and OpCo GP. OpCo and Westlake entered into an ethylene sales agreement (the "Ethylene Sales Agreement") pursuant to which the Partnership generates a substantial majority of its revenue. For more information, see Note 8. Basis of Presentation The accompanying unaudited consolidated interim financial statements were prepared in accordance with the rules and regulations of the Securities and Exchange Commission (the "SEC") for interim periods. Accordingly, certain information and footnotes required for complete financial statements under generally accepted accounting principles in the United States ("U.S. GAAP") have not been included. These interim consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto of the Partnership included in the annual report on Form 10-K for the fiscal year ended December 31, 2025 (the "2025 Form 10-K"), filed with the SEC on March 4, 2026. These financial statements have been prepared in conformity with the accounting principles and practices as disclosed in the notes to the consolidated financial statements of the Partnership for the fiscal year ended December 31, 2025. The Partnership holds a 22.8 % limited partner interest and the entire non-economic general partner interest in OpCo. The remaining 77.2 % limited partner interest in OpCo is owned directly by Westlake, which has no rights to direct the activities that most significantly impact the economic performance of OpCo. As a result of the fact that substantially all of OpCo's activities are conducted on behalf of Westlake, and the fact that OpCo exhibits disproportionality of voting rights to economic interest, OpCo was deemed to be a variable interest entity. The Partnership, through its ownership of OpCo's general partner, has the power to direct the activities that most significantly impact the economic performance of OpCo, and it also has the obligation or right to absorb losses or receive benefits from OpCo that could potentially be significant to OpCo. As such, the Partnership was determined to be OpCo's primary beneficiary and therefore consolidates OpCo's results of operations and financial position. The Partnership's operations consist exclusively of the variable interest entity's operations and, as such, no additional variable interest entity disclosures are considered necessary. Westlake's retained interest of 77.2 % is recorded as noncontrolling interest in the Partnership's consolidated financial statements. In the opinion of the Partnership's management, the accompanying unaudited consolidated interim financial statements reflect all adjustments (consisting only of normal recurring adjustments) that are necessary for a fair statement of the Partnership's financial position as of March 31, 2026, its results of operations for the three months ended March 31, 2026 and 2025 and the changes in its cash position for the three months ended March 31, 2026 and 2025. Results of operations and changes in cash position for the interim periods presented are not necessarily indicative of the results that will be realized for the fiscal year ending December 31, 2026 or any other interim period. The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities. Actual results could differ materially from those estimates. 6 Table of Contents WESTLAKE CHEMICAL PARTNERS LP NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — Continued (Unaudited) (in thousands of dollars, except unit amounts and per unit data) Recently Issued Accounting Pronouncement Disaggregation of Income Statement Expenses (ASU No. 2024-03) In November 2024, the FASB issued an accounting standards update requiring public entities to disclose, on an annual and interim basis, detailed information about the types of expenses in relevant expense captions presented on the face of the income statement, including amounts for inventory purchases, employee compensation, depreciation and amortization of intangible assets and a qualitative description for remaining amounts not separately disaggregated. Additionally, the update requires disclosure of total selling expenses, and in annual periods, an entity's definition of selling expenses. The amendments in this update are effective for annual reporting periods beginning after December 15, 2026, and interim periods beginning after December 15, 2027 and are to be applied either prospectively or retrospectively. Early adoption is permitted. The Partnership is currently evaluating the impact of the update on the disclosures in the Partnership's consolidated financial statements. Recently Adopted Accounting Pronouncement Measurement of Credit Losses for Accounts Receivable and Contract Assets (ASU No. 2025-05) In July 2025, the Financial Accounting Standards Board ("FASB") issued an accounting standards update to add a practical expedient in developing reasonable and supportable forecasts as part of estimating expected credit losses. All entities may elect a practical expedient that assumes the current conditions as of the balance sheet date do not change for the remaining life of the asset. The amendments in this update are effective for annual reporting periods beginning after December 15, 2025 and interim reporting periods within those annual reporting periods, with early adoption permitted. Entities should apply the new guidance prospectively. The Partnership adopted the standard electing a practical expedient effective January 1, 2026, and the adoption of this accounting standard did not have a material impact on its consolidated statements of financial position, results of operations, or cash flows, or on related financial statement disclosures. 2. Accounts Receivable—Third Parties Accounts receivable—third parties consisted of the following: March 31, 2026 December 31, 2025 Trade customers $ 20,044 $ 9,283 Allowance for credit losses ( 266 ) ( 170 ) Accounts receivable, net—third parties $ 19,778 $ 9,113 3. Inventories Inventories consisted of the following: March 31, 2026 December 31, 2025 Finished products $ 2,542 $ 2,336 Feedstock, additives and chemicals 551 433 Inventories $ 3,093 $ 2,769 4. Property, Plant and Equipment Depreciation expense on property, plant and equipment of $ 22,339 and $ 20,836 is included in cost of sales in the consolidated statements of operations for the three months ended March 31, 2026 and 2025, respectively. 5. Deferred Charges and Other Assets Amortization expense on deferred charges and other assets of $ 11,960 and $ 6,232 is included in cost of sales in the consolidated statements of operations for the three months ended March 31, 2026 and 2025, respectively . 7 Table of Contents WESTLAKE CHEMICAL PARTNERS LP NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — Continued (Unaudited) (in thousands of dollars, except unit amounts and per unit data) 6. Distributions and Net Income Per Limited Partner Unit On May 4, 2026, the board of directors of Westlake Chemical Partners GP LLC ("Westlake GP"), the Partnership's general partner, declared a quarterly cash distribution for the three months ended March 31, 2026 of 0.4714 per common unit. This distribution is payable on June 1, 2026 to unitholders of record as of May 14, 2026. Distributions are declared subsequent to quarter end; therefore, the table below represents total cash distributions declared from earnings of the related periods pertaining to such distributions. Three Months Ended March 31, 2026 2025 Net income attributable to the Partnership $ 14,169 $ 4,948 Less: Limited partners' distribution declared on common units 16,615 16,611 Distribution in excess of net income $ ( 2,446 ) $ ( 11,663 ) Net income per unit applicable to common limited partner units is computed by dividing the respective limited partners' interest in net income by the weighted-average number of common units outstanding for the period. Because the Partnership has more than one class of participating securities, it uses the two-class method when calculating the net income per unit applicable to limited partners. The classes of participating securities include common units and incentive distribution rights. Net income attributable to the Partnership is allocated to the unitholders in accordance with their respective ownership percentages in preparation of the consolidated statements of changes in equity. However, in the event distributions related to the incentive distribution rights are made, net income equal to the amount of those distributions would first be allocated to the general partner before the remaining net income would be allocated to the unitholders based on their respective ownership percentages. Basic and diluted net income per unit is the same because the Partnership does not have any potentially dilutive units outstanding for the periods presented. Three Months Ended March 31, 2026 Limited Partners' Common Units Incentive Distribution Rights Total Net income attributable to the Partnership: Distribution $ 16,615 $ — $ 16,615 Distribution in excess of net income ( 2,446 ) — ( 2,446 ) Net income $ 14,169 $ — $ 14,169 Weighted average units outstanding: Basic and diluted 35,245,879 35,245,879 Net income per limited partner unit: Basic and diluted $ 0.40 Three Months Ended March 31, 2025 Limited Partners' Common Units Incentive Distribution Rights Total Net income attributable to the Partnership: Distribution $ 16,611 $ — $ 16,611 Distribution in excess of net income ( 11,663 ) — ( 11,663 ) Net income $ 4,948 $ — $ 4,948 Weighted average units outstanding: Basic and diluted 35,238,556 35,238,556 Net income per limited partner unit: Basic and diluted $ 0.14 8 Table of Contents WESTLAKE CHEMICAL PARTNERS LP NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — Continued (Unaudited) (in thousands of dollars, except unit amounts and per unit data) The amended Partnership Agreement provides that the Partnership will distribute cash that is deemed to be an appropriate portion of the Partnership's total operating surplus. Incentive distribution rights represent the right to receive increasing percentages ( 15.0 %, 25.0 % and 50.0 %) of quarterly distributions from operating surplus after the target distribution levels have been achieved. If cash distributions to the Partnership's unitholders exceed $ 1.2938 per common unit in any quarter, the Partnership's unitholders and Westlake, as the holder of the Partnership's incentive distribution rights, will receive distributions according to the following percentage allocations: Marginal Percentage Interest in Distributions Unitholders IDR Holders Above $ 1.2938 up to $ 1.4063 85.0 % 15.0 % Above $ 1.4063 up to $ 1.6875 75.0 % 25.0 % Above $ 1.6875 50.0 % 50.0 % If cash distributions to the Partnership's unitholders do not exceed $ 1.2938 per common unit in a quarter, then no distribution is made with respect to the Partnership's incentive distribution rights for such quarter. The Partnership's distribution for the three months ended March 31, 2026 was $ 0.4714 per common unit, which did not exceed the $ 1.2938 per unit threshold, and, as a result, no distribution was made with respect to the Partnership's incentive distribution rights to Westlake, as the holder of the Partnership's incentive distribution rights. Distributions Per Common Unit Distributions per common unit for the three months ended March 31, 2026 and 2025 were as follows: Three Months Ended March 31, 2026 2025 Distributions per common unit $ 0.4714 $ 0.4714 7. Partners' Equity On October 4, 2018, the Partnership and Westlake Chemical Partners GP LLC, the general partner of the Partnership, entered into an Equity Distribution Agreement with UBS Securities LLC, Barclays Capital Inc., Citigroup Global Markets Inc., Deutsche Bank Securities Inc., RBC Capital Markets, LLC, Merrill Lynch, Pierce, Fenner & Smith Incorporated and Wells Fargo Securities, LLC to offer and sell the Partnership's common units, from time to time, up to an aggregate offering amount of $ 50,000 . The Equity Distribution Agreement was amended on February 28, 2020 to reference a new shelf registration and subsequent renewals thereof for utilization under this agreement. To date, no common units have been issued under this program. On March 29, 2019, the Partnership completed the issuance and sale of 2,940,818 common units at a price of $ 21.40 per unit through a private placement. TTWF LP, Westlake's principal stockholder and a related party, acquired 1,401,869 common units out of 2,940,818 common units issued in the private placement. 9 Table of Contents WESTLAKE CHEMICAL PARTNERS LP NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — Continued (Unaudited) (in thousands of dollars, except unit amounts and per unit data) 8. Related Party Transactions Related party transactions between the Partnership, OpCo and Westlake are primarily based on agreements such as the Ethylene Sales Agreement, the Feedstock Supply Agreement, the Services and Secondment Agreement, Site Lease Agreements, the Omnibus Agreement, the Investment Management Agreement, the Exchange Agreement, the OpCo Partnership Agreement, the OpCo Revolver and the MLP Revolver. These agreements, discussed in detail in the Partnership's 2025 consolidated financial statements included in the 2025 Form 10-K filed on March 4, 2026, reflect the pervasive effect of the relationship with Westlake on the Partnership's operations and its consolidated financial statements. Pursuant to these agreements, the Partnership and OpCo regularly enter into transactions with Westlake. See below for descriptions and details of significant related party transactions. Sales to Related Parties OpCo sells ethylene to Westlake under the Ethylene Sales Agreement. Additionally, the Partnership and OpCo from time to time provide other services or products for which it charges Westlake a fee. OpCo sells a significant portion of its ethylene production to Westlake. Sales to related parties were as follows: Three Months Ended March 31, 2026 2025 Net sales—Westlake $ 263,091 $ 190,781 During the quarter ended March 31, 2026, OpCo's production resulted in expected "excess quantities" of ethylene produced based on annual estimated production. Pursuant to the terms of the Ethylene Sales Agreement, the excess quantities produced by the Partnership were sold to Westlake at prices that excluded certain fixed costs of production. The fixed cost of production associated with the estimated excess quantities for the quarter ended March 31, 2026 was approximately $ 800 . Cost of Sales from Related Parties Charges for goods and services purchased by the Partnership and OpCo from Westlake and included in cost of sales relate primarily to feedstock purchased under the Feedstock Supply Agreement and services provided under the Services and Secondment Agreement. A significant portion of the Partnership's inputs included in cost of sales are supplied by Westlake. Charges from related parties for significant inputs included in cost of sales were as follows: Three Months Ended March 31, 2026 2025 Feedstock purchased from Westlake and included in cost of sales $ 97,061 $ 85,499 Other charges from Westlake and included in cost of sales 38,205 31,477 Services from Related Parties Included in Selling, General and Administrative Expenses Charges for services purchased by the Partnership from Westlake and included in selling, general and administrative expenses primarily relate to services Westlake performs on behalf of the Partnership under the Omnibus Agreement, including the Partnership's finance, legal, information technology, human resources, communication, ethics and compliance and other administrative functions. Charges from related parties included within selling, general and administrative expenses were as follows: Three Months Ended March 31, 2026 2025 Services received from Westlake and included in selling, general and administrative expenses $ 6,419 $ 6,431 10 Table of Contents WESTLAKE CHEMICAL PARTNERS LP NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — Continued (Unaudited) (in thousands of dollars, except unit amounts and per unit data) Goods and Services from Related Parties Capitalized as Assets Charges for goods and services purchased by the Partnership and OpCo from Westlake, which were capitalized as assets, relate primarily to the services of Westlake employees under the Services and Secondment Agreement. Charges from related parties for goods and services capitalized as assets were as follows: Three Months Ended March 31, 2026 2025 Goods and services purchased from Westlake and capitalized as assets $ 541 $ 5,428 Receivable under the Investment Management Agreement On August 1, 2017, the Partnership, OpCo and Westlake executed an investment management agreement (the "Investment Management Agreement") that authorized Westlake to invest the Partnership's and OpCo's excess cash with Westlake for durations of up to a maximum of nine months. Per the terms of the Investment Management Agreement, the Partnership earns a market return plus five basis points and Westlake provides daily availability of the invested cash to meet any liquidity needs of the Partnership or OpCo. Accrued interest of $ 269 and $ 206 was included in the receivable under the Investment Management Agreement balance at March 31, 2026 and December 31, 2025, respectively. Total interest earned related to the Investment Management Agreement was $ 269 and $ 1,357 for the three months ended March 31, 2026 and 2025, respectively. The Partnership's receivable under the Investment Management Agreement was as follows: March 31, 2026 December 31, 2025 Receivable under the Investment Management Agreement $ 36,441 $ 23,378 Accounts Receivable from Related Parties The Partnership's accounts receivable from Westlake result primarily from ethylene sales to Westlake and any Buyer Deficiency Fee and Shortfall recognized under the Ethylene Sales Agreement. As of December 31, 2025, OpCo had an annual production deficiency under the Ethylene Sales Agreement for the full year 2025 primarily due to the Petro 1 turnaround extending into April 2025, which was later than the planned completion in March 2025. The Buyer Deficiency Fee is measured periodically based upon the lower of the actual production deficiency at period end or the estimated annual production deficiency based upon OpCo's annual anticipated production. These periodic estimates are updated at the end of the year based on actual annual production. The Buyer Deficiency Fee is classified as a component of net sales—Westlake. The total Buyer Deficiency Fee recognized by the Partnership during the twelve months ended December 31, 2025 was $ 5,835 . The Buyer Deficiency Fee recognized in 2025 was received by the Partnership in January 2026. The Partnership's accounts receivable from Westlake were as follows: March 31, 2026 December 31, 2025 Accounts receivable—Westlake $ 45,082 $ 63,571 Accounts Payable to Related Parties The Partnership's accounts payable to Westlake result primarily from feedstock purchases under the Feedstock Supply Agreement and services provided under the Services and Secondment Agreement and the Omnibus Agreement. The Partnership's accounts payable to Westlake were as follows: March 31, 2026 December 31, 2025 Accounts payable—Westlake $ 8,706 $ 19,132 11 Table of Contents WESTLAKE CHEMICAL PARTNERS LP NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — Continued (Unaudited) (in thousands of dollars, except unit amounts and per unit data) Related Party Leases OpCo is obligated to Westlake under various long-term and short-term noncancelable operating leases, primarily related to rail cars and land. Operating lease rentals paid to Westlake for such leases were $ 437 and $ 338 for the three months ended March 31, 2026 and 2025, respectively, an d are reflected in other charges from Westlake that are included in cost of sales. OpCo has two site lease agreements with Westlake, each of which has a term of 50 years. Pursuant to the site lease agreements, OpCo pays Westlake one dollar per site per year. Debt Payable to Related Parties See Note 9 for a description of related party debt payable balances. Interest on related party debt payable balances, net of capitalized interest, for the three months ended March 31, 2026 and 2025 was $ 5,085 and $ 5,537 , respecti vely. Interest on related party debt payable is presented as interest expense—Westlake in the consolidated statements of operations. At March 31, 2026 and December 31, 2025, accrued interest on related party debt was $ 5,085 and $ 5,508 , respectively, and is reflected as a component of accrued and other liabilities in the consolidated balance sheets. Debt payable to related parties was as follows: March 31, 2026 December 31, 2025 Long-term debt payable to Westlake $ 399,674 $ 399,674 Major Customer and Concentration of Credit Risk During the three months ended March 31, 2026 and 2025, Westlake accounted for approximately 86.1 % and 80.3 %, respectively, of the Partnership's net sale s. 9. Long-Term Debt Long-term debt payable to Westlake consisted of the following: March 31, 2026 December 31, 2025 OpCo Revolver $ 22,619 $ 22,619 MLP Revolver 377,055 377,055 Long-term debt payable to Westlake $ 399,674 $ 399,674 As of March 31, 2026, outstanding borrowings under the OpCo Revolver and the MLP Revolver bore interest at the Secured Overnight Financing Rate, as administered by the Federal Reserve Bank of New York ("SOFR") plus the Applicable Margin plus a 0.10 % credit spread adjustment. The Applicable Margin under the OpCo Revolver is 1.75 %. The Applicable Margin under the MLP Revolver varies between 1.75 % and 2.75 %, depending on the Partnership's Consolidated Leverage Ratio. The OpCo Revolver and the MLP Revolver are scheduled to mature on July 12, 2027. The weighted average interest rate on all long-term debt was 5.5 % and 5.8 % at March 31, 2026 and December 31, 2025, respectively. As of March 31, 2026, the Partnership was in compliance with all of the covenants under the OpCo Revolver and the MLP Revolver. 12 Table of Contents WESTLAKE CHEMICAL PARTNERS LP NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — Continued (Unaudited) (in thousands of dollars, except unit amounts and per unit data) 10. Fair Value Measurements The Partnership reports certain assets and liabilities at fair value, which is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). Under the accounting guidance for fair value measurements, inputs used to measure fair value are classified in one of three levels: Level 1: Quoted market prices in active markets for identical assets or liabilities. Level 2: Observable market-based inputs or unobservable inputs that are corroborated by market data. Level 3: Unobservable inputs that are not corroborated by market data. The Partnership has financial assets and liabilities subject to fair value measures. These financial assets and liabilities include cash and cash equivalents, accounts receivable, net, accounts payable and long-term debt payable to Westlake, all of which are recorded at carrying value. The amounts reported in the consolidated balance sheets for cash and cash equivalents, accounts receivable, net and accounts payable approximate their fair value due to the short maturities of these instruments. The carrying and fair values of the Partnership's long-term debt at March 31, 2026 and December 31, 2025 are summarized in the table below. The fair value of long-term debt is determined based on the present value of expected future cash flows using a discounted cash flow methodology. Because the Partnership's valuation methodology used for long-term debt requires the use of significant unobservable inputs, the inputs used to measure the fair value of the Partnership's long-term debt are classified as Level 3 within the fair value hierarchy. Inputs used to estimate the fair values of the Partnership's long-term debt include the selection of an appropriate discount rate. March 31, 2026 December 31, 2025 Carrying Value Fair Value Carrying Value Fair Value Long-term debt payable to Westlake $ 399,674 $ 409,399 $ 399,674 $ 408,780 13 Table of Contents WESTLAKE CHEMICAL PARTNERS LP NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — Continued (Unaudited) (in thousands of dollars, except unit amounts and per unit data) 11. Supplemental Information Accrued and Other Liabilities Accrued and other liabilities were $ 21,847 and $ 22,199 at March 31, 2026 and December 31, 2025, respectively. Accrued taxes, accrued turnaround costs, accrued PP&E capital expenditures and accrued interest on related party debt, which are components of accrued and other liabilities, were $ 3,409 , $ 5,082 , $ 2,892 and $ 5,085 , respectively, at March 31, 2026 and $ 2,104 , $ 6,372 , $ 994 and $ 5,508 , respectively, at December 31, 2025. No other component of accrued and other liabilities was more than five percent of total current liabilities. Cash Flow Information Non-cash Investing Activity Capital expenditure related liabilities, included in accounts payable—third parties and accrued and other liabilities, were $ 5,681 and $ 14,756 at March 31, 2026 and 2025, respectively. Operating Leases There were no right-of-use assets obtained in exchange for operating lease obligations for the three months ended March 31, 2026. Right-of-use assets for operating lease obligations for the three months ended March 31, 2025 were $ 173 , respectively. 12. Commitments and Contingencies The Partnership is subject to environmental laws and regulations that can impose civil and criminal sanctions and that may require the Partnership to mitigate the effects of contamination caused by the release or disposal of hazardous substances into the environment. These laws include the federal Clean Air Act, the federal Water Pollution Control Act, the Resource Conservation and Recovery Act, the Comprehensive Environmental Response, Compensation, and Liability Act ("CERCLA"), the Toxic Substances Control Act and various other federal, state and local laws and regulations. Under CERCLA, an owner or operator of property may be held strictly liable for remediating contamination without regard to whether that person caused the contamination, and without regard to whether the practices that resulted in the contamination were legal at the time they occurred. Because the Partnership's production sites have a history of industrial use, it is impossible to predict precisely what effect these legal requirements will have on the Partnership. Pursuant to the Omnibus Agreement, certain subsidiaries of Westlake will indemnify the Partnership for certain environmental and other liabilities that occurred or existed prior to August 4, 2014. Pursuant to the Services and Secondment Agreement, certain subsidiaries of Westlake will indemnify the Partnership for certain liabilities incurred in connection with the performance of Westlake's services under such agreement. The Partnership is also involved in other legal proceedings incidental to the conduct of its business. After considering all relevant facts and circumstances, including applicable insurance and indemnification by Westlake, the Partnership does not believe that any of these legal proceedings will have a material adverse effect on its financial condition, results of operations or cash flows. 14 Table of Contents WESTLAKE CHEMICAL PARTNERS LP NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — Continued (Unaudited) (in thousands of dollars, except unit amounts and per unit data) 13. Segment Information The Partnership has one operating segment, which is the Partnership's reportable segment, OpCo. Consolidated net sales and provision for income taxes as disclosed in the consolidated statements of operations and depreciation and amortization and additions to property, plant and equipment as disclosed in the consolidated statements of cash flows are fully attributed to the OpCo segment, and as such, separate OpCo segment amounts are not repeated in the tables below. Three Months Ended March 31, 2026 2025 Significant segment expenses and other segment items OpCo Raw material, energy, manufacturing and logistics costs $ 177,617 $ 156,480 Depreciation and amortization 34,299 27,068 Total cost of sales 211,916 183,548 Selling, general and administrative expenses 6,228 6,672 Other segment items (1) 141 ( 971 ) Interest expense—Westlake OpCo $ 312 $ 268 Corporate 4,773 5,269 $ 5,085 $ 5,537 Net income OpCo $ 87,390 $ 48,380 A reconciliation of total segment net income to consolidated net income is as follows: Three Months Ended March 31, 2026 2025 Net income from OpCo $ 87,390 $ 48,380 Corporate net loss ( 5,735 ) ( 6,071 ) Net income $ 81,655 $ 42,309 March 31, 2026 December 31, 2025 Total assets OpCo $ 1,201,556 $ 1,222,123 Corporate 34,142 34,410 $ 1,235,698 $ 1,256,533 _____________________________ (1) Other segment items includes interest expense—Westlake, other income, net and provision for income taxes. 15 Table of Contents