Capstone Copper (ASX:CSC) agreed to sell its Cozamin copper-silver-zinc-lead mine in Zacatecas, Mexico to Luca Mining in a deal valued at up to $385 million, according to a late Monday statement by the company.

The consideration comprises $275 million in upfront cash, $15 million in Luca shares, $35 million in deferred payments, and up to $60 million in contingent cash tied to annual average copper prices.

The company said it will use the proceeds to bolster its balance sheet and enhance financial flexibility to support its growth pipeline.

The transaction is expected to close in the fourth quarter, subject to customary conditions and regulatory approvals, including Mexican antitrust clearance.