Capstone Copper to resume full production at Chile’s Mantoverde mine as strike ends

Canada’s Capstone Copper (TSX: CS) said on Friday that the largest union at its Mantoverde copper‑gold mine in Chile had approved a new three‑year labour contract, ending a strike that started on January 2 and paving the way for production to return to normal.

Shares of the miner’s Australia-listed depositary receipts CSC.AX fell as much as 3.9% to A$15.430, their lowest since January 23.

The agreement brings an end to a labour strike that had reduced production at the mine to about 55% of normal levels.

Capstone said it had now negotiated new contracts with all the four unions at the site, allowing the company to resume full operations.

Union No. 2, representing around 645 workers or roughly 50% of Mantoverde’s direct workforce, had led the strike after rejecting a payment offer as labour negotiations broke down.

The company did not disclose details of the new payment offer or any further terms of the agreement.

In 2025, Mantoverde produced 62,308 metric tons of copper concentrate and 32,807 tons of copper cathodes, accounting or about 0.4% of global production.

Capstone owns a 70% stake in Mantoverde, while Japan’s Mitsubishi Materials 5711.T holds the remaining 30%.

(Reporting by Kumar Tanishk in Bengaluru; Editing by Subhranshu Sahu)