The Indonesian state-owned firm will pay $3.5 billion to Rio Tinto for its complete interest in the mine, and $350 million to majority owner Freeport for an additional 9.36% stake.
Freeport and the Indonesian government came to an agreement last August after a long-running dispute, while Rio has reportedly been looking for an exit from the mine since October last year.
Rio owns the right to 40% of Grasberg's production above a pre-agreed level and 40% of all production after 2022. In 2017, Rio claimed 5700 tonnes of the total 468,000t production.
Macquarie said Rio's sale price was $900 million above its estimates.
"We view the outcome as a positive for Rio with the deal expected to be completed before the end of 2018," Macquarie said.<...