TORONTO, Aug 7 (Reuters) - Canada's main stock index closed at its highest level in more than a month on Tuesday, led by energy and mining shares, on investor hopes that the European Central Bank will move to combat the region's sovereign debt crisis. The Toronto Stock Exchange's S&P/TSX composite index unofficially closed up 200.91 points, or 1.7 percent, at 11,863.50. The second straight session of solid gains took the index to its highest close since July 4.