BHP Billiton Limited (ASX:BHP, NYSE:BHP) and Rio Tinto Limited (ASX:RIO, NYSE:RIO) will spend $US 4 billion to increase copper production at the Escondida copper mine in Chile.
BHP will spend $US 2.2 billion and Rio $US 1.2 billion to replace a concentrator at the mine with a new plant.
Construction will start this month and is expected to be completed in 2015.
BHP has also announced a 25 per cent increase in ore reserves at Escondida.
BHP reported a net profit of $9.88 billion for the half year ended December 31, 2011.
