wlkp-20260630

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 10-Q


☒	QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
	For the quarterly period ended	June 30, 2026


☐			TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
			For the Transition Period from to

Commission File No. 001-36567

Westlake Chemical Partners LP

(Exact name of registrant as specified in its charter)


Delaware						32-0436529
(State or other jurisdiction of incorporation or organization)						(I.R.S. Employer Identification No.)

2801 Post Oak Boulevard, Suite 600

Houston, Texas 77056

(Address of principal executive offices, including zip code)

(713) 585-2900

(Registrant's telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:


Title of each class	Trading Symbol(s)	Name of each exchange on which registered
Common units representing limited partnership interests	WLKP	The New York Stock Exchange

Indicate by check mark whether the registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes x No ¨

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes x No ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See definitions of "large accelerated filer", "accelerated filer", "smaller reporting company" and "emerging growth company" in Rule 12b-2 of the Exchange Act:

Large accelerated filer

Accelerated filer

Non-accelerated filer

Smaller reporting company

☐

Emerging growth company

☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ¨

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act) Yes ☐ No x

The registrant had 35,245,879 common units outstanding as of July 29, 2026.

Table of Contents

TABLE OF CONTENTS


		Page
	PART I. FINANCIAL INFORMATION
Item
1)	Financial Statements	1
2)	Management's Discussion and Analysis of Financial Condition and Results of Operations	18
3)	Quantitative and Qualitative Disclosures about Market Risk	30
4)	Controls and Procedures	30

	PART II. OTHER INFORMATION

1)	Legal Proceedings	31
1A)	Risk Factors	31
5)	Other Information	31
6)	Exhibits	32

Table of Contents

PART I. FINANCIAL INFORMATION

Item 1. Financial Statements

WESTLAKE CHEMICAL PARTNERS LP

CONSOLIDATED BALANCE SHEETS

(Unaudited)


	June 30, 2026		December 31, 2025

	(in thousands of dollars, except unit amounts)
ASSETS
Current assets
Cash and cash equivalents	$	49,321	$	44,269
Receivable under the Investment Management Agreement—Westlake Corporation ("Westlake")	43,577		23,378
Accounts receivable, net—Westlake	39,464		63,571
Accounts receivable, net—third parties	21,602		9,113
Inventories	3,563		2,769
Prepaid expenses and other current assets	10		406
Total current assets	157,537		143,506
Property, plant and equipment, net	858,643		886,012
Goodwill	5,814		5,814
Deferred charges and other assets, net	195,354		221,201
Total assets	$	1,217,348	$	1,256,533
LIABILITIES
Current liabilities
Accounts payable—Westlake	$	15,630	$	19,132
Accounts payable—third parties	11,003		9,970
Accrued and other liabilities	19,135		22,199

Total current liabilities	45,768		51,301
Long-term debt payable to Westlake	399,674		399,674
Deferred income taxes	1,494		1,546
Other liabilities	999		1,660
Total liabilities	447,935		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 June 30, 2026 and December 31, 2025, respectively)	457,957		460,848
Common unitholder—Westlake (14,122,230 and 14,122,230 units issued and outstanding at June 30, 2026 and December 31, 2025, respectively)	38,328		40,260
General partner—Westlake	(242,572)		(242,572)

Total Westlake Chemical Partners LP partners' capital	253,713		258,536
Noncontrolling interest in Westlake Chemical OpCo LP ("OpCo")	515,700		543,816
Total equity	769,413		802,352
Total liabilities and equity	$	1,217,348	$	1,256,533

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

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WESTLAKE CHEMICAL PARTNERS LP

CONSOLIDATED STATEMENTS OF OPERATIONS

(Unaudited)


	Three Months Ended June 30,				Six Months Ended June 30,
	2026		2025		2026		2025

	(in thousands of dollars, except unit amounts and per unit data)
Revenue
Net sales—Westlake	$	238,030	$	269,076	$	501,121	$	459,857
Net co-products, ethylene and other sales—third parties	59,070		28,043		101,654		74,891
Total net sales	297,100		297,119		602,775		534,748
Cost of sales	202,295		199,587		414,211		383,135
Gross profit	94,805		97,532		188,564		151,613
Selling, general and administrative expenses	7,494		6,300		14,684		13,774
Income from operations	87,311		91,232		173,880		137,839
Other income (expense)
Interest expense—Westlake	(5,119)		(5,907)		(10,204)		(11,444)
Other income, net	348		675		696		2,021
Income before income taxes	82,540		86,000		164,372		128,416
Provision for income taxes	178		205		355		312
Net income	82,362		85,795		164,017		128,104
Less: Net income attributable to noncontrolling interest in OpCo	68,124		71,237		135,610		108,598
Net income attributable to Westlake Chemical Partners LP and limited partners' interest in net income	$	14,238	$	14,558	$	28,407	$	19,506
Net income per limited partner unit attributable to Westlake Chemical Partners LP (basic and diluted)
Common units	$	0.40	$	0.41	$	0.81	$	0.55
Weighted average limited partner units outstanding (basic and diluted)
Common units—publicly and privately held	21,123,649		21,116,326		21,123,649		21,116,326
Common units—Westlake	14,122,230		14,122,230		14,122,230		14,122,230

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

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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

Net income		8,533		5,705		—		68,124		82,362



Distribution to unitholders		(9,958)		(6,657)		—		—		(16,615)
Distribution to noncontrolling interest retained in OpCo by Westlake		—		—		—		(88,720)		(88,720)
Balances at June 30, 2026		$	457,957	$	38,328	$	(242,572)	$	515,700	$	769,413

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

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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

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

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

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WESTLAKE CHEMICAL PARTNERS LP

CONSOLIDATED STATEMENTS OF CASH FLOWS

(Unaudited)


	Six Months Ended June 30,
	2026		2025

	(in thousands of dollars)
Cash flows from operating activities
Net income	$	164,017	$	128,104
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	69,327		59,552
Loss from disposition of property, plant and equipment	2,188		491
Other losses, net	168		33
Changes in operating assets and liabilities
Accounts receivable—third parties	(12,709)		(1,239)
Net accounts receivable—Westlake	20,406		(39,483)
Inventories	(794)		797
Prepaid expenses and other current assets	396		420
Accounts payable—third parties	(1,293)		11,302
Accrued and other liabilities	(2,741)		17,590
Deferred charges and other assets and others, net	1,080		(122,715)
Net cash provided by operating activities	240,045		54,852
Cash flows from investing activities
Additions to property, plant and equipment	(18,037)		(40,336)
Investments with Westlake under the Investment Management Agreement	(20,000)		—
Maturities of investments with Westlake under the Investment Management Agreement	—		90,000

Net cash provided by (used for) investing activities	(38,037)		49,664
Cash flows from financing activities

Proceeds from debt payable to Westlake	82,000		95,000
Repayment of debt payable to Westlake	(82,000)		(95,000)
Distributions to noncontrolling interest retained in OpCo by Westlake	(163,726)		(93,031)
Distributions to unitholders	(33,230)		(33,222)
Net cash used for financing activities	(196,956)		(126,253)
Net increase (decrease) in cash and cash equivalents	5,052		(21,737)
Cash and cash equivalents at beginning of period	44,269		58,316
Cash and cash equivalents at end of period	$	49,321	$	36,579

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

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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 June 30, 2026, its results of operations for the three and six months ended June 30, 2026 and 2025 and the changes in its cash position for the six months ended June 30, 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.

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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:


	June 30, 2026		December 31, 2025
Trade customers	$	21,992	$	9,283
Allowance for credit losses	(390)		(170)


Accounts receivable, net—third parties	$	21,602	$	9,113

3. Inventories

Inventories consisted of the following:


	June 30, 2026		December 31, 2025
Finished products	$	3,049	$	2,336
Feedstock, additives and chemicals	514		433
Inventories	$	3,563	$	2,769

4. Property, Plant and Equipment

Depreciation expense on property, plant and equipment of $22,913 and $21,587 is included in cost of sales in the consolidated statements of operations for the three months ended June 30, 2026 and 2025, respectively. Depreciation expense on property, plant and equipment of $45,252 and $42,423 is included in cost of sales in the consolidated statements of operations for the six months ended June 30, 2026 and 2025, respectively.

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WESTLAKE CHEMICAL PARTNERS LP

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—Continued

(Unaudited)

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

5. Deferred Charges and Other Assets

Amortization expense on deferred charges and other assets of $12,115 and $10,897 is included in cost of sales in the consolidated statements of operations for the three months ended June 30, 2026 and 2025, respectively. Amortization expense on deferred charges and other assets of $24,075 and $17,129 is included in cost of sales in the consolidated statements of operations for the six months ended June 30, 2026 and 2025, respectively.

6. Distributions and Net Income Per Limited Partner Unit

On August 3, 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 June 30, 2026 of 0.4714 per common unit. This distribution is payable on August 28, 2026 to unitholders of record as of August 13, 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 June 30,				Six Months Ended June 30,
	2026		2025		2026		2025
Net income attributable to the Partnership	$	14,238	$	14,558	$	28,407	$	19,506
Less:
Limited partners' distribution declared on common units	16,615		16,612		33,230		33,223


Distribution in excess of net income	$	(2,377)	$	(2,054)	$	(4,823)	$	(13,717)

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 June 30, 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	(2,377)		—		(2,377)
Net income	$	14,238	$	—	$	14,238
Weighted average units outstanding:
Basic and diluted	35,245,879				35,245,879
Net income per limited partner unit:
Basic and diluted	$	0.40

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WESTLAKE CHEMICAL PARTNERS LP

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—Continued

(Unaudited)

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


	Three Months Ended June 30, 2025
	Limited Partners' Common Units		Incentive Distribution Rights		Total
Net income attributable to the Partnership:
Distribution	$	16,612	$	—	$	16,612
Distribution in excess of net income	(2,054)		—		(2,054)
Net income	$	14,558	$	—	$	14,558
Weighted average units outstanding:
Basic and diluted	35,238,556				35,238,556
Net income per limited partner unit:
Basic and diluted	$	0.41


	Six Months Ended June 30, 2026
	Limited Partners' Common Units		Incentive Distribution Rights		Total
Net income attributable to the Partnership:
Distribution	$	33,230	$	—	$	33,230
Distribution in excess of net income	(4,823)		—		(4,823)
Net income	$	28,407	$	—	$	28,407
Weighted average units outstanding:
Basic and diluted	35,245,879				35,245,879
Net income per limited partner unit:
Basic and diluted	$	0.81


	Six Months Ended June 30, 2025
	Limited Partners' Common Units		Incentive Distribution Rights		Total
Net income attributable to the Partnership:
Distribution	$	33,223	$	—	$	33,223
Distribution in excess of net income	(13,717)		—		(13,717)
Net income	$	19,506	$	—	$	19,506
Weighted average units outstanding:
Basic and diluted	35,238,556				35,238,556
Net income per limited partner unit:
Basic and diluted	$	0.55

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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 June 30, 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 six months ended June 30, 2026 and 2025 were as follows:


	Three Months Ended June 30,				Six Months Ended June 30,
	2026		2025		2026		2025
Distributions per common unit	$	0.4714	$	0.4714	$	0.9428	$	0.9428

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.

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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 June 30,				Six Months Ended June 30,
	2026		2025		2026		2025
Net sales—Westlake	$	238,030	$	269,076	$	501,121	$	459,857

As of June 30, 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 six months ended June 30, 2026 was approximately $2,100.

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 June 30,				Six Months Ended June 30,
	2026		2025		2026		2025
Feedstock purchased from Westlake and included in cost of sales	$	86,595	$	90,567	$	183,656	$	176,066
Other charges from Westlake and included in cost of sales	34,748		33,729		72,953		65,206

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 June 30,				Six Months Ended June 30,
	2026		2025		2026		2025
Services received from Westlake and included in selling, general and administrative expenses	$	6,618	$	5,276	$	13,037	$	11,707