Rio Invests $350 Million in Diamond Project After Walsh Backing

Rio Tinto Group, the world’s second biggest mining company, approved a $350 million project to expand a diamond mine in northwestern Canada, weeks after Chief Executive Officer Sam Walsh flagged an investment.

Construction of the A21 kimberlite pipe at the Diavik mine, 220 kilometers (140 miles) south of the Arctic Circle, will start next year, London-based Rio Tinto said today in a statement. Rio owns 60 percent of the mine, with Dominion Diamond Corp. holding the remainder.