TORONTO, Sept 12 (Reuters) - Canada's main stock index posted its biggest gain in three months on Tuesday, led by financial sector gains, while resource shares also climbed, helped by higher oil prices and watchdog approval of a merger between potash producers.
The Toronto Stock Exchange's S&P/TSX composite index .GSPTSE unofficially closed up 103.11 points, or 0.69 percent, at 15,143.41. Nine of its 10 main groups ended higher.