Rio Tinto sells copper mine stake to Sumitomo for $399 million

Sumitomo will pay $195 million upfront and $204 million in deferred payments contingent on development progress, Rio said in a statement Wednesday. The London-based miner added that the companies would explore additional partnerships across copper, other base metals and lithium.

“This is a unique opportunity to derisk our investment,” Rio’s chief executive of copper, Katie Jackson, said. “We look forward to working more broadly as strategic partners to find new ways to deliver value across the metals and minerals supply chain.”

The Winu copper-gold deposit in the remote Great Sandy Desert region of Western Australia was discovered by Rio in 2017 and is yet to be developed, according to the statement. A pre-feasibility study into building a mine will be released in 2025.

Like peer BHP Group Ltd., Rio is keen to grow its exposure to copper — a key metal used in electrification. Still, the Winu deposit is considered a smaller project in comparison to its Escondida mine in Chile.