USA Rare Earth to take stake in Carester and deepen rare-earth partnership in France

USA Rare Earth says it will take a strategic stake in French rare-earth processor Carester and deepen a cross-border supply-chain partnership.

In an April 9, 2026 press release, the company said it and InfraVia plan to acquire minority stakes in Carester, with USA Rare Earth targeting about a 12.5% holding. The agreement is designed to connect USA Rare Earth’s Round Top feedstock ambitions with Carester’s processing and metals capabilities in France.

The companies said the partnership gives USA Rare Earth and its LCM Europe unit access to Carester’s Caremag output, engineering expertise and intellectual property. In return, Carester gains long-term access to heavy rare-earth feedstock from USA Rare Earth’s Round Top deposit.

The deal is tied to industrial development in Lacq, France, where Carester is advancing its rare-earth processing platform. Carester’s own materials describe Caremag as a recycling and refining project expected to begin operations in late 2026.

The announcement adds another sign of how rare-earth companies are trying to build more integrated supply chains outside China, linking mining, processing and downstream metals work across borders. The companies have not yet said when the transaction will close or what final valuation will apply.