What changed in this filing

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Item 1. Financial Statements

2026-05-06 compared with 2025-10-31 · 80 added, 166 removed, 340 unchanged (42% of the section changed)

2 unchanged sentences

CONSOLIDATED BALANCE SHEETS

September 30,

2026 December 31,

23 unchanged sentences

Common unitholders—publicly and privately held ( 21,123,649 and 21,123,649 units

issued and outstanding at September 30, 2025 and December 31, 2024, respectively)

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 September 30, 2025 and December 31, 2024, respectively)

outstanding at March 31, 2026 and December 31, 2025, respectively)

39,280 40,260

7 unchanged sentences

CONSOLIDATED STATEMENTS OF OPERATIONS

Three Months Ended September 30, Nine Months Ended September 30,

2025 2024 2025 2024

Three Months Ended March 31,

(in thousands of dollars, except unit amounts and per unit data)

33 unchanged sentences

Balances at March 31, 2026 $ 459,382 $ 39,280 $ ( 242,572 ) $ 536,296 $ 792,386

Net income 8,724 5,834 — 71,237 85,795

Distribution to unitholders ( 9,954 ) ( 6,657 ) — — ( 16,611 )

Distribution to noncontrolling interest retained in OpCo by Westlake — — — ( 41,125 ) ( 41,125 )

Balances at June 30, 2025 $ 463,109 $ 41,876 $ ( 242,572 ) $ 568,752 $ 831,165

Net income 8,781 5,872 — 71,561 86,214

Units issued for vested phantom units 161 — — — 161

Distribution to unitholders ( 9,958 ) ( 6,657 ) — — ( 16,615 )

Distribution to noncontrolling interest retained in OpCo by Westlake — — — ( 87,614 ) ( 87,614 )

Balances at September 30, 2025 $ 462,093 $ 41,091 $ ( 242,572 ) $ 552,699 $ 813,311

The accompanying notes are an integral part of the consolidated financial statements.

12 unchanged sentences

Balances at March 31, 2025 $ 464,339 $ 42,699 $ ( 242,572 ) $ 538,640 $ 803,106

Net income 8,644 5,783 — 73,599 88,026

Units issued for vested phantom units 55 — — — 55

Distribution to unitholders ( 9,950 ) ( 6,657 ) — — ( 16,607 )

Distribution to noncontrolling interest retained in OpCo by Westlake — — — ( 84,872 ) ( 84,872 )

Balances at June 30, 2024 $ 471,199 $ 47,408 $ ( 242,572 ) $ 558,812 $ 834,847

Net income 10,867 7,269 — 85,964 104,100

Units issued for vested phantom units 183 — — — 183

Distribution to unitholders ( 9,953 ) ( 6,657 ) — — ( 16,610 )

Distribution to noncontrolling interest retained in OpCo by Westlake — — — ( 84,706 ) ( 84,706 )

Balances at September 30, 2024 $ 472,296 $ 48,020 $ ( 242,572 ) $ 560,070 $ 837,814

The accompanying notes are an integral part of the consolidated financial statements.

1 unchanged sentence

CONSOLIDATED STATEMENTS OF CASH FLOWS

Nine Months Ended September 30,

Three Months Ended March 31,

(in thousands of dollars)

4 unchanged sentences

Loss from disposition of property, plant and equipment 61 103

Other losses (gains), net

Other losses, net

Changes in operating assets and liabilities

21 unchanged sentences

Net increase (decrease) in cash and cash equivalents

( 20,380 ) 1,589

Cash and cash equivalents at beginning of period 44,269 58,316

8 unchanged sentences

On August 4, 2014, the Partnership completed its initial public offering (the "IPO") of 12,937,500 common units representing limited partner interests.

In connection with the IPO, the Partnership acquired a 10.6 % 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 (collectively, the "Contributed Assets").

Since the IPO, the Partnership has periodically purchased additional limited partner interest in OpCo.

Most recently, on March 29, 2019, the Partnership purchased an additional 4.5 % newly-issued limited partner interest in OpCo for approximately $ 201,445 , resulting in an aggregate 22.8 % limited partner interest in OpCo, effective January 1, 2019.

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

4 unchanged sentences

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.

References to "Westlake" refer collectively to Westlake Corporation and its subsidiaries, other than the Partnership, OpCo and OpCo GP.

The Partnership holds a 22.8 % limited partner interest and the entire non-economic general partner interest in OpCo.

5 unchanged sentences

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 September 30, 2025, its results of operations for the three and nine months ended September 30, 2025 and 2024 and the changes in its cash position for the nine months ended September 30, 2025 and 2024.

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.

5 unchanged sentences

(in thousands of dollars, except unit amounts and per unit data)

Recently Issued Accounting Pronouncements

Measurement of Credit Losses for Accounts Receivable and Contract Assets (ASU No.

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 does not expect that this accounting standard, upon adoption, will have a material impact on the Partnership's consolidated financial statements.

Recently Issued Accounting Pronouncement

Disaggregation of Income Statement Expenses (ASU No.

4 unchanged sentences

The Partnership is currently evaluating the impact of the update on the disclosures in the Partnership's consolidated financial statements.

Income Taxes (ASU No.

In December 2023, the FASB issued an accounting standards update requiring additional tax disclosures primarily related to the rate reconciliation and income taxes paid disclosures.

The amendments in this update will be effective for annual periods beginning after December 15, 2024 and are to be applied on a prospective basis.

Retrospective application is also permitted.

The update is not expected to have a material impact on the disclosures in the Partnership's consolidated financial statements.

Recently Adopted Accounting Pronouncement

Segment Reporting (ASU No.

In November 2023, the FASB issued an accounting standards update requiring public entities to disclose on an annual and interim basis, significant segment expenses that are regularly provided to the chief operating decision maker ("CODM") and on an annual basis, the title and position of the CODM and an explanation of how the CODM uses the reported measure(s) of segment profit or loss in assessing segment performance and deciding how to allocate resources.

The update also requires that a public entity that has a single reportable segment provide all disclosures required by the update as well as all existing segment disclosures in Topic 280.

The amendments in this update are effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024 and are to be applied retrospectively to all prior periods presented in the financial statements.

Early adoption is permitted.

The Partnership adopted this accounting standard effective for the annual 2024 financial statements and interim period financial statements thereafter, and the adoption resulted in additional segment disclosures (see Note 13).

Measurement of Credit Losses for Accounts Receivable and Contract Assets (ASU No.

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.

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.

Accounts Receivable—Third Parties

Accounts receivable—third parties consist of the following:

September 30,

Accounts receivable—third parties consisted of the following:

2026 December 31,

2 unchanged sentences

Accounts receivable, net—third parties $ 19,778 $ 9,113

WESTLAKE CHEMICAL PARTNERS LP

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — Continued

(in thousands of dollars, except unit amounts and per unit data)

Inventories consist of the following:

September 30,

Inventories consisted of the following:

2026 December 31,

3 unchanged sentences

Property, Plant and Equipment

Depreciation expense on property, plant and equipment of $ 21,966 and $ 21,626 is included in cost of sales in the consolidated statements of operations for the three months ended September 30, 2025 and 2024, respectively.

Depreciation expense on property, plant and equipment of $ 64,389 and $ 64,993 is included in cost of sales in the consolidated statements of operations for the nine months ended September 30, 2025 and 2024 , respectively.

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.

Deferred Charges and Other Assets

Amortization expense on deferred charges and other assets of $ 11,906 and $ 6,486 is included in cost of sales in the consolidated statements of operations for the three months ended September 30, 2025 and 2024, respectively .

Amortization expense on deferred charges and other assets of $ 29,035 and $ 19,428 is included in cost of sales in the consolidated statements of operations for the nine months ended September 30, 2025 and 2024, respectively.

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 .

WESTLAKE CHEMICAL PARTNERS LP

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — Continued

(in thousands of dollars, except unit amounts and per unit data)

Distributions and Net Income Per Limited Partner Unit

On October 28, 2025, 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 September 30, 2025 of 0.4714 per common unit.

This distribution is payable on November 26, 2025 to unitholders of record as of November 10, 2025.

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 September 30, Nine Months Ended September 30,

2025 2024 2025 2024

Three Months Ended March 31,

Net income attributable to the Partnership $ 14,169 $ 4,948

Limited partners' distribution declared on common units 16,615 16,611

Net income in excess of distribution (Distribution in excess of net income)

Distribution in excess of net income

$ ( 2,446 ) $ ( 11,663 )

3 unchanged sentences

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, when distributions related to the incentive distribution rights are made, net income equal to the amount of those distributions is first allocated to the general partner before the remaining net income is allocated to the unitholders based on their respective ownership percentages.

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.

WESTLAKE CHEMICAL PARTNERS LP

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — Continued

(in thousands of dollars, except unit amounts and per unit data)

Three Months Ended September 30, 2025

Three Months Ended March 31, 2026

Limited Partners' Common Units Incentive Distribution Rights Total

8 unchanged sentences

Basic and diluted $ 0.40

Three Months Ended September 30, 2024

Limited Partners' Common Units Incentive Distribution Rights Total

Net income attributable to the Partnership:

Distribution $ 16,611 $ — $ 16,611

Net income in excess of distribution 1,525 — 1,525

Net income $ 18,136 $ — $ 18,136

Weighted average units outstanding:

Basic and diluted 35,235,173 35,235,173

Net income per limited partner unit:

Basic and diluted $ 0.51

Nine Months Ended September 30, 2025

Three Months Ended March 31, 2025

Limited Partners' Common Units Incentive Distribution Rights Total

2 unchanged sentences

Distribution in excess of net income

( 11,663 ) — ( 11,663 )

Net income $ 4,948 $ — $ 4,948

6 unchanged sentences

(in thousands of dollars, except unit amounts and per unit data)

Nine Months Ended September 30, 2024

Limited Partners' Common Units Incentive Distribution Rights Total

Net income attributable to the Partnership:

Distribution $ 49,826 $ — $ 49,826

Distribution in excess of net income ( 2,430 ) — ( 2,430 )

Net income $ 47,396 $ — $ 47,396

Weighted average units outstanding:

Basic and diluted 35,230,961 35,230,961

Net income per limited partner unit:

Basic and diluted $ 1.35

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

Total Quarterly Distribution Per Unit Unitholders IDR Holders

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 %

The Partnership's distribution for the three months ended September 30, 2025 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.

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 and nine months ended September 30, 2025 and 2024 were as follows:

Three Months Ended September 30, Nine Months Ended September 30,

2025 2024 2025 2024

Distributions per common unit for the three months ended March 31, 2026 and 2025 were as follows:

Three Months Ended March 31,

Distributions per common unit $ 0.4714 $ 0.4714

2 unchanged sentences

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.

No common units were issued under this program as of September 30, 2025.

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.

13 unchanged sentences

Sales to related parties were as follows:

Three Months Ended September 30, Nine Months Ended September 30,

2025 2024 2025 2024

Three Months Ended March 31,

Net sales—Westlake $ 263,091 $ 190,781

As of September 30, 2025, OpCo forecasted 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.

As a result, the Partnership recognized buyer deficiency fees of $ 13,613 in the second quarter of 2025.

The total buyer deficiency fees recognized by the Partnership during the nine months ended September 30, 2025 was $ 13,613 .

The buyer deficiency fee is measured based upon the lower of the actual production deficiency at period end or the estimated annual production deficiency.

The buyer deficiency fees are classified as a component of net sales—Westlake.

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

2 unchanged sentences

Charges from related parties for significant inputs included in cost of sales were as follows:

Three Months Ended September 30, Nine Months Ended September 30,

2025 2024 2025 2024

Three Months Ended March 31,

Feedstock purchased from Westlake and included in cost of sales $ 97,061 $ 85,499

3 unchanged sentences

Charges from related parties included within selling, general and administrative expenses were as follows:

Three Months Ended September 30, Nine Months Ended September 30,

2025 2024 2025 2024

Three Months Ended March 31,

Services received from Westlake and included in selling, general and administrative expenses $ 6,419 $ 6,431

5 unchanged sentences

Charges from related parties for goods and services capitalized as assets were as follows:

Three Months Ended September 30, Nine Months Ended September 30,

2025 2024 2025 2024

Three Months Ended March 31,

Goods and services purchased from Westlake and capitalized as assets $ 541 $ 5,428

2 unchanged sentences

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 $ 224 and $ 1,385 was included in the receivable under the Investment Management Agreement balance at September 30, 2025 and December 31, 2024, respectively.

Total interest earned related to the Investment Management Agreement was $ 224 and $ 1,368 for the three months ended September 30, 2025 and 2024, respectively, and $ 2,333 and $ 3,979 for the nine months ended September 30, 2025 and 2024, respectively.

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:

September 30,

2026 December 31,

1 unchanged sentence

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 fee recognized under the Ethylene Sales Agreement.

The buyer deficiency fees discussed above under "Sales to Related Parties" recognized in the nine months ended September 30, 2025 are scheduled to be received by the Partnership after December 31, 2025.

As a result of the Partnership's decision to postpone the maintenance turnaround at the Petro 1 facility from the third quarter of 2024 to the first quarter of 2025, OpCo's production resulted in "excess quantities" of ethylene for the contract year ended December 31, 2024.

Pursuant to the terms of the Ethylene Sales Agreement, the excess quantities produced were sold to Westlake at prices that excluded certain non-variable costs of production.

As of December 31, 2024, accounts receivable included sales associated with the excess quantities, which were at a lower sales price.

WESTLAKE CHEMICAL PARTNERS LP

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — Continued

(in thousands of dollars, except unit amounts and per unit data)

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:

September 30,

2026 December 31,

3 unchanged sentences

The Partnership's accounts payable to Westlake were as follows:

September 30,

2026 December 31,

Accounts payable—Westlake $ 8,706 $ 19,132

WESTLAKE CHEMICAL PARTNERS LP

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — Continued

(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 $ 468 and $ 471 for the three months ended September 30, 2025 and 2024, respectively, and $ 1,246 and $ 1,326 for the nine months ended September 30, 2025 and 2024 respectively, an d are reflected in other charges from Westlake that are included in cost of sales.

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.

2 unchanged sentences

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 September 30, 2025 and 2024 was $ 5,947 and $ 6,698 , respecti vely.

Interest on related party debt payable balances, net of capitalized interest, for the nine months ended September 30, 2025 and 2024 was $ 17,391 and $ 19,930 , respectively.

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 September 30, 2025 and December 31, 2024, accrued interest on related party debt was $ 5,945 and $ 5,848 , respectively, and is reflected as a component of accrued and other liabilities in the consolidated balance sheets.

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:

September 30,

2026 December 31,

1 unchanged sentence

Major Customer and Concentration of Credit Risk

During the three months ended September 30, 2025 and 2024, Westlake accounted for approximately 89.5 % and 77.9 %, respectively, of the Partnership's net sale s.

During the nine months ended September 30, 2025 and 2024, Westlake accounted for approximately 87.3 % and 81.6 % , respectively, of the Partnership's net sales.

WESTLAKE CHEMICAL PARTNERS LP

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — Continued

(in thousands of dollars, except unit amounts and per unit data)

Long-Term Debt Payable to Westlake

Long-term debt payable to Westlake consists of the following:

September 30,

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.

Long-Term Debt

Long-term debt payable to Westlake consisted of the following:

2026 December 31,

2 unchanged sentences

Long-term debt payable to Westlake $ 399,674 $ 399,674

As of September 30, 2025, 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.

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 %.

1 unchanged sentence

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 6.1 % and 6.4 % at September 30, 2025 and December 31, 2024, respectively.

As of September 30, 2025, the Partnership was in compliance with all of the covenants under the OpCo Revolver and the MLP Revolver.

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.

WESTLAKE CHEMICAL PARTNERS LP

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — Continued

(in thousands of dollars, except unit amounts and per unit data)

Fair Value Measurements

7 unchanged sentences

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 September 30, 2025 and December 31, 2024 are summarized in the table below.

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.

1 unchanged sentence

Inputs used to estimate the fair values of the Partnership's long-term debt include the selection of an appropriate discount rate.

September 30, 2025 December 31, 2024

March 31, 2026 December 31, 2025

Value Carrying

5 unchanged sentences

Accrued and Other Liabilities

Accrued and other liabilities were $ 32,036 and $ 16,920 at September 30, 2025 and December 31, 2024, respectively.

Accrued taxes, accrued turnaround costs and accrued interest on related party debt, which are components of accrued and other liabilities, were $ 6,177 , $ 12,649 and $ 5,945 , respectively, at September 30, 2025 and $ 2,415 , $ 933 and $ 5,848 , respectively, at December 31, 2024.

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.

1 unchanged sentence

Non-cash Investing Activity

Capital expenditure related liabilities, included in accounts payable—third parties and accrued and other liabilities, were $ 5,768 and $ 7,376 at September 30, 2025 and 2024, respectively.

Interest Paid

Interest paid by the Partnership, net of interest capitalized, was $ 17,292 and $ 19,852 for the nine months ended September 30, 2025 and 2024, respectively.

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

Right-of-use assets obtained in exchange for operating lease obligations were $ 920 and $ 758 for the nine months ended September 30, 2025 and 2024, respectively.

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.

Commitments and Contingencies

13 unchanged sentences

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 September 30, Nine Months Ended September 30,

2025 2024 2025 2024

Three Months Ended March 31,

Significant segment expenses and other segment items

4 unchanged sentences

Other segment items (1)

175 ( 749 ) ( 913 ) ( 2,168 )

Interest expense—Westlake

4 unchanged sentences

A reconciliation of total segment net income to consolidated net income is as follows:

Three Months Ended September 30, Nine Months Ended September 30,

2025 2024 2025 2024

Three Months Ended March 31,

Net income from OpCo

3 unchanged sentences

$ 81,655 $ 42,309

September 30,

2026 December 31,

4 unchanged sentences

(1) Other segment items includes interest expense—Westlake, other income, net and provision for income taxes.

WESTLAKE CHEMICAL PARTNERS LP

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — Continued

(in thousands of dollars, except unit amounts and per unit data)

Subsequent Events

On October 28, 2025, OpCo and Westlake agreed to renew both the Ethylene Sales Agreement and the Feedstock Supply Agreement through December 31, 2027 in accordance with their respective terms (the "Renewal"), which each provide 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.

In connection with the Renewal, on October 28, 2025, OpCo and certain affiliates of Westlake entered into an amendment to the Services and Secondment Agreement to align the date of expiration of such agreement with the date of expiration term of the Ethylene Sales Agreement.

In addition, the Partnership, OpCo and certain affiliates of Westlake also entered into an amendment to the Omnibus Agreement to provide that the Omnibus Agreement would terminate upon termination of the Ethylene Sales Agreement.

The amendment also addressed certain procedural requirements in connection with Westlake's obligation to indemnify the Partnership for certain matters, including, among others, environmental and tax matters, under the Omnibus Agreement.

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.

What changed 10-Q

Item 1. Financial Statements