Baker McKenzie has advised U.S. mining investor Orion Resources and British investor Audley Capital Advisors on the sale of a 30% stake in a copper mine in Chile's Atacama region.

Mitsubishi Materials Corp. of Japan bought the stake in the Mantoverde copper mine owned by Mantos Copper Holding SpA for a $263 million equity subscription and a $20 million cash payment upon fulfillment of certain milestones.

Simmons & Simmons acted as London counsel to Mantos Copper. Iain Duncan, a partner in the energy, natural resources and infrastructure group, has counseled Mantos in the past.

Antonio Ortúzar, a Baker McKenzie partner in Chile, said the deal required explanation of complex mining tenements, tax compliance and detailing of assets such as water to the purchaser's in-house legal counsel.

Baker McKenzie partners Jaime Munro and Mirco Hilgers also helped with the sale.

The Mantoverde assets corresponded to multiple legal schemes, with some property registered under positive law that required translation into common law.

Furthermore, the purchaser and Mantoverde entered into a copper concentrates sales and purchase agreement.

The transaction is subject to the execution of a project financing package and regulatory approvals and is expected to close in the second half of 2020.