Capstone Copper Corp. (ASX:CSC), an Americas-focused copper mining company headquartered in Vancouver, Canada, has announced that Union #2 at its Mantoverde Mine in Chile will commence strike action effective January 2, 2026. Union #2 represents approximately 50% of the Mantoverde employees, equating to around 22% of the total workforce at the mine. Capstone Copper’s operating portfolio of assets includes the Pinto Valley copper mine located in Arizona, USA, the Cozamin copper-silver mine located in Zacatecas, Mexico, the Mantos Blancos copper-silver mine located in the Antofagasta region, Chile, and the Mantoverde copper-gold mine, located in the Atacama region, Chile.
Prior to the strike notice, Capstone Copper engaged in good faith negotiations with Union #2 to reach a new collective bargaining agreement. As a result of the impending strike, the company will gradually reduce certain activities at the Mantoverde mine in a safe and responsible manner. Capstone Copper anticipates that operations will continue, albeit at a reduced level, with production expected to reach up to 30% of normal capacity during the strike.
Capstone Copper has expressed its willingness to continue discussions to achieve a resolution and remains committed to adhering to all legal procedures. The company respects the rights of its employees and invites the union to participate in constructive dialogue. Capstone Copper will provide all requested information to the authorities. The company emphasised its commitment to integrity and transparency and looks forward to resuming safe and responsible mining practices at Mantoverde.
In 2025, Mantoverde successfully negotiated new three-year collective bargaining agreements with the other three unions. In 2024, Capstone Copper contributed $682 million in economic value to Chile across its operations, including $136 million in employee wages and benefits. Mantoverde employs approximately 1,270 employees, including about 550 from local communities in the Atacama region of Chile.