What changed in this filing

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Item 1. Business

2026-03-04 compared with 2025-03-05 · 19 added, 12 removed, 147 unchanged (17% of the section changed)

20 unchanged sentences

OpCo primarily uses ethane (a component of natural gas liquids, or NGLs) to produce ethylene.

We remain focused on our ability to continue to provide long-term value and distributions to our unitholders.

As we navigate market conditions, we evaluate future growth opportunities, including the following four potential levers:

• increases of our ownership interest in OpCo;

• acquisitions of other qualified income streams;

• organic growth opportunities such as expansions of our current ethylene facilities;

• negotiation of a higher fixed-margin in our Ethylene Sales Agreement with Westlake.

Ownership of Westlake Chemical Partners LP

48 unchanged sentences

Ethylene Sales Agreement

OpCo and Westlake are parties to the Ethylene Sales Agreement, which has 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 12-months' notice.

On October 28, 2025, OpCo and Westlake agreed to renew the Ethylene Sales Agreement through December 31, 2027 in accordance with its terms.

The Ethylene Sales Agreement requires Westlake to purchase OpCo's planned ethylene production each year, subject to certain exceptions and a maximum commitment of 3.8 billion pounds per year, less product sold by OpCo to third parties equal to approximately 5% of the annual output.

8 unchanged sentences

Under the Ethylene Sales Agreement, OpCo has the option to curtail up to approximately 5% of its ethylene production annually in the event OpCo reasonably determines that its sales of such ethylene to third parties during the relevant period would be uneconomic.

Pursuan t to the Ethylene Sales Agreement, Westlake's obligation to pay for the annual minimum commitment (95% of OpCo's budgeted ethylene production), which is measured on an annual basis, is not reduced for a force majeure event lasting fewer than 45 consecutive days.

In the event of a force majeure event, the Partnership recognizes buyer deficiency fees representing fixed margin and unavoided operating and maintenance capital expenditures and maintenance expenses per pound of volume committed by Westlake during the force majeure p eriod.

In the event Westlake purchases less than its annual commitment, we recognize buyer deficiency fees representing fixed margin and all expenses and expenditures incurred per pound of volume committed but not taken by Westlake.

Payment for the buyer deficiency fee is scheduled to be received by the Partnership after the conclusion of the year in which the force majeure event occurred.

Pursuant to the Ethylene Sales Agreement, Westlake is obligated to pay for the annual minimum quantity (95% of OpCo's budgeted ethylene production), which is measured on an annual basis.

In the event Westlake purchases less than its annual commitment, we recognize a buyer deficiency fee ( " Buyer Deficiency Fee " ) representing fixed margin and all expenses and expenditures incurred per pound of volume committed but not taken by Westlake.

The annual commitment is not reduced for a force majeure event affecting OpCo's plants that lasts fewer than 45 consecutive days;

however, in the event of such a force majeure event, the Partnership recognizes a Buyer Deficiency Fee representing fixed margin and unavoided operating and maintenance capital expenditures and maintenance expenses per pound of volume committed by Westlake during the force majeure period.

Payment of the Buyer Deficiency Fee is scheduled to be received by the Partnership after the conclusion of the year in which the annual commitment was not purchased and taken by Westlake.

Under the Ethylene Sales Agreement, if production costs billed to Westlake on an annual basis are less than 95% of the actual production costs incurred by OpCo during the contract year, OpCo is entitled to recover the shortfall in such production costs (proportionate to the volume sold to Westlake) in the subsequent year ("Shortfall").

2 unchanged sentences

Feedstock Supply Agreement

OpCo and Westlake are parties to the Feedstock Supply Agreement, which has 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 12-months' notice.

On October 28, 2025, OpCo and Westlake agreed to renew the Feedstock Supply Agreement through December 31, 2027 in accordance with its terms.

Under the Feedstock Supply Agreement, Westlake sells OpCo ethane and other feedstock in amounts sufficient for OpCo to produce the ethylene to be sold under the Ethylene Sales Agreement.

2 unchanged sentences

OpCo and Westlake are parties to the Services and Secondment Agreement, pursuant to which OpCo provides Westlake with various utilities and utility services in exchange for Westlake providing OpCo with various utility services, comprehensive operating services for OpCo's units, services for the maintenance and operation of the common facilities and seconded employees to perform all services required under the agreement.

In connection with the renewals of the Ethylene Sales Agreement and the Feedstock Supply Agreement, 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 of the Ethylene Sales Agreement.

Site Lease Agreements

8 unchanged sentences

Under the Omnibus Agreement, Westlake will indemnify us against certain environmental and other losses, and we will indemnify Westlake against certain environmental and other losses for which Westlake is not otherwise obligated to indemnify us and certain other losses and liabilities to the extent resulting from the provision of services by Westlake to us.

In connection with the renewals of the Ethylene Sales Agreement and the Feedstock Supply Agreement, on October 28, 2025, the Partnership, OpCo and certain affiliates of Westlake entered into an amendment to the Omnibus Agreement to provide that the Omnibus Agreement would terminate upon termination of the Ethylene Sales Agreement.

Exchange Agreement

33 unchanged sentences

As of December 31, 2025, 155 employees of Westlake were seconded to OpCo.

Of these, 25 are covered by collective bargaining agreements.

On November 1, 2024, bargaining unit employees of Local Lodge No.

2781 of the International Association of Machinists and Aerospace Workers ("IAM") began a strike at our Calvert City, Kentucky, facility, after the IAM members, who work in the OpCo's ethylene facility and Westlake's chlorine units, did not accept Westlake's final offer for a new collective bargaining agreement.

The ethylene unit continued to operate without disruption with the use of management and other salaried personnel.

The strike ended on November 8, 2024, after the IAM accepted Westlake's offer for a new collective bargaining agreement, which will expire on November 9, 2029.

Despite the recent strike, we believe that Westlake's relationship with local union officials and bargaining committees is open and positive.

As of December 31, 2025, 15% of such seconded employees were covered by a collective bargaining agreement, which will expire in November 2029.

We believe that Westlake's relationship with local union representatives is open and positive.

Westlake is responsible for human capital management policies, including any human capital measures and objectives that management focuses on in managing the business.

12 unchanged sentences

Compared sentence by sentence after normalising whitespace, quotation marks, case and digits, so re-formatting and restated figures do not read as changed language. Wording changes appear as one removal and one addition. The current filing and the prior one are authoritative.

What changed 10-K

Item 1. Business