Westlake Chemical Partners LP (NYSE: WLKP) is a master limited partnership that produces and sells ethylene through its ownership interest in Westlake Chemical OpCo LP. The partnership's sole revenue-generating asset is its 22.8% limited partner interest in OpCo, which sells virtually all of its ethylene output to parent company Westlake Chemical Corporation under a long-term Ethylene Sales Agreement. That agreement, extended through December 31, 2027 as of October 28, 2025, obligates Westlake to purchase at least 95% of OpCo's budgeted annual ethylene production, with pricing structured to pass through feedstock costs, operating expenses, maintenance capital, and a fixed margin per pound. OpCo owns three ethylene production facilities, two at Lake Charles, Louisiana (combined annual capacity approximately 3 billion pounds) and one at Calvert City, Kentucky (annual capacity approximately 730 million pounds), plus a 200-mile common carrier ethylene pipeline running from Mont Belvieu, Texas to Longview, Texas. Public unitholders held 59.9% of common units and Westlake held the remaining 40.1% plus incentive distribution rights as of December 31, 2025.

Revenue model

Revenue flows almost entirely from ethylene sales to Westlake Chemical Corporation under the Ethylene Sales Agreement. Pricing passes through feedstock costs, natural gas, labor, utilities, and turnaround expenses, plus a fixed margin per pound. If Westlake purchases less than its annual 95% commitment, OpCo collects a Buyer Deficiency Fee covering fixed margin and all incurred expenses on uncommitted volume. Operating expenses other than feedstock and utilities are forecast-based and built into the per-pound price charged to Westlake, with any shortfall recoverable in the subsequent contract year.

Products and services

Ethylene produced at three facilities: Lake Charles Olefins (Petro 1 and Petro 2, Lake Charles, Louisiana; combined annual capacity approximately 3 billion pounds as of December 31, 2025), Calvert City Olefins (Calvert City, Kentucky; annual capacity approximately 730 million pounds as of December 31, 2025), and a 200-mile common carrier ethylene pipeline (Mont Belvieu, Texas to Longview, Texas; capacity 3.5 million pounds per day). OpCo holds perpetual, paid-up licenses for steam cracking and process recovery technology used at its ethylene plants.

Customers and end markets

Westlake Chemical Corporation is effectively the sole customer, obligated to purchase at least 95% of OpCo's budgeted annual ethylene production under the Ethylene Sales Agreement. Customer concentration is total: the partnership has no disclosed revenue from any other buyer. Ethylene is a petrochemical feedstock used downstream by Westlake in polyethylene and other chemical production.

Value-chain role

Westlake Chemical Partners sits upstream as an ethylene producer and pipeline operator, supplying feedstock to its parent Westlake Chemical Corporation's downstream polyethylene and chemical manufacturing operations. The partnership functions as a toll-like, cost-plus entity: it produces ethylene, recovers all production costs plus a fixed margin from Westlake, and distributes available cash to unitholders. The common carrier Longview Pipeline connects third-party ethylene infrastructure at Mont Belvieu to Westlake's Longview PE facility.

Geographic exposure

All operations are in the United States. Production facilities are in Lake Charles, Louisiana and Calvert City, Kentucky. The Longview Pipeline runs within Texas from Mont Belvieu to Longview. No international operations are disclosed in the filing.

Source: SEC 10-K, filed 2026-03-04

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