Related Party Transactions

3 Months Ended

Mar. 31, 2026

Related Party Transactions [Abstract]

Related Party Transactions

2.    Related Party Transactions

The significant related party transactions occurring during the three months ended March 31, 2026 and 2025 are described below. All of our related party transactions are subject to the Company's Related Party Transaction Policy and are required to be made on an arm's length basis and on terms that are fair and reasonable to the Company and substantially the same as would

apply if the other party was not a related party. We believe all of our transactions with related parties are at prices that approximate market.

Glencore Ownership

As of March 31, 2026, Glencore plc and its affiliates (together "Glencore") beneficially owned 30.0% of Century’s outstanding common stock. Century and Glencore enter into various transactions from time to time, such as the purchase and sale of primary aluminum, alumina and other raw materials; tolling agreements; forward financial contracts and borrowing and other debt transactions.

Sales to Glencore

For the three months ended March 31, 2026 and 2025, we derived approximately 47.1% and 59.7%, respectively, of our consolidated net sales from Glencore.

Glencore purchases aluminum produced at our U.S. smelters at prices based on the London Metal Exchange ("LME") plus the Midwest regional delivery premium plus any additional market-based product premiums. Glencore purchases aluminum produced at our Grundartangi, Iceland smelter at prices based on the LME plus the European Duty Paid premium plus any additional market-based product premiums.

We have entered into agreements with Glencore pursuant to which we sell certain amounts of alumina at market-based prices. For the three months ended March 31, 2026 and 2025, the Company recognized $61.3 million and $78.4 million, respectively, of revenue related to alumina sales to Glencore.

Purchases from Glencore

We purchase a portion of our alumina and certain other raw material requirements from Glencore. Alumina purchases from Glencore during the three months ended March 31, 2026 and 2025 were priced based on aluminum indices.

Summary

A summary of the aforementioned significant related party sales and purchases is as follows: 

	Three months ended March 31,
	2026		2025
Net sales to Glencore	$	305.9	$	378.7
Purchases from Glencore	64.2		88.3

Vlissingen Credit Facility

On December 9, 2022, Vlissingen entered into a Facility Agreement with Glencore International AG, which was amended and extended on October 1, 2024 (as amended, the “Vlissingen Credit Facility”). The availability period for borrowings under the Vlissingen Credit Facility was extended by two years and now ends on December 2, 2026. Under the Vlissingen Credit Facility, Vlissingen may borrow from time to time up to $90.0 million in one or more loans at a variable interest rate equal to the 1-month SOFR rate plus 3.687 percentage points, subject to an absolute maximum level of 9.00% and an absolute minimum level of 7.00%. As of March 31, 2026, there were no outstanding borrowings under the Vlissingen Credit Facility. See Note 12. Debt for additional information. Borrowings under the Vlissingen Credit Facility are expected to be used for general corporate and working capital purposes of Century and its subsidiaries.