For nearly three decades, the world's number two copper mine has been controlled by an American company. As of Tuesday, that changed.

Phoenix-based Freeport-McMoRan agreed to give up its majority stake in the massive Grasberg gold and copper mine, ceding control to the Indonesian government.

The Grasberg Mine is by some measures the largest gold mine in the world and the second largest copper mine.

Freeport’s ownership will be reduced from 90 percent to 49 percent.

Freeport and its local subsidiary have conducted mining and exploration activities since 1988.

Control of the mine will also give Indonesia sovereignty over the mine’s natural resources. F

Freeport has agreed to build a new processing and refining facility and, if other conditions are met, will be allowed to operate the project until 2041.