Rio Tinto approves $667 mln Pilbara investment

SYDNEY, June 18 (Reuters) - Global miner Rio Tinto (RIO.AX) (RIO.L) has approved a $667 million investment in its Pilbara mining region in Australia, under a previously announced plan to boost iron-ore output there to 320 million tonnes a year by 2012.

Rio said on Wednesday its share of the investment in the overall project was $492 million. The company is defending a hostile takeover bid from BHP Billiton Ltd (BHP.AX) (BLT.L). ($1=A$1.06) (Reporting by Denny Thomas, editing by Mark Bendeich) ((denny.thomas@reuters.com; +61 2 9373 1812; Reuters Messaging: denny.thomas.reuters.com@reuters.net))