Capstone Copper’s Chilean workers ready to strike if mediation fails

Reuters | December 24, 2025 | 12:12 pm Latin America Copper Gold

The Mantoverde operation in Chile is 70% owned by Capstone Copper and 30% by Misubishi Materials. Credit: Mantos Copper

Workers at Capstone Copper’s (TSX: CS) Mantoverde copper and gold mine in Chile are ready to strike if mediation for a new labor contract fails, with a walkout potentially starting December 29, the union said on Wednesday.

The 645-member union rejected a contract offer in mid-December, opening the door to a strike.

An initial five-day government mediation period is under way and can be extended by a further five days if both parties agree.

The company “has not made new proposals that allow the talks to advance,” the union said in a statement.

The union said it is prepared for an extended strike that could cost the company over $100 million per month in lost revenue.

Mantoverde is 70% owned by Capstone Copper and 30% by Mitsubishi Minerals. The mine is expected to produce 29,000-32,000 metric tons of copper cathodes in 2025.

(Reporting by Fabian Cambero; Editing by Chris Reese)