TORONTO, July 18 (Reuters) - Canada's main stock index fell broadly in early trading on Tuesday, as financial and material heavyweights led declines.

The Toronto Stock Exchange's S&P/TSX composite index fell 25.51 points, or 0.17 percent, to 15,139.85 shortly after the open.

Energy was the only group out of the index's 10 key sectors that advanced. (Reporting by Solarina Ho)