TORONTO, Sept 26 (Reuters) - Canada's main stock index retreated on Tuesday, after posting a 4-month high the day before, as a drop in commodity prices weighed on the shares of energy and mining companies.
The Toronto Stock Exchange's S&P/TSX composite index .GSPTSE was down 33.15 points, or 0.21 percent, at 15,483.08, shortly after the open. Nine of the index's 10 main groups lost ground.