The US company, which operates the Grasberg mine through its 90.64%-owned PT Freeport Indonesia (PT-FI) subsidiary, is providing information to assist the sale process but has no control over its outcome, Richard Adkerson said.

“The Indonesian government is in discussions with our joint-venture partner with the potential of acquiring their interest,” Adkerson said during a conference call for its 2017 earnings.

“We are cooperating and helping to facilitate that transaction...That transaction, if it goes ahead, would be the best outcome for everyone, I believe,” he added.

The transaction "appears to be the desire of the parties" and was the "most likely outcome." Adkerson said

Rio Tinto has a joint venture with Freeport for a 40% share of production above specific levels until 2021, and 40% of all production after 2021.

Freeport is also currently negotiating to divest its stake in PT-FI to give the government a 51% stake.