* TSX down 81.95 points, or 0.64 percent, at 12,796.63 * Energy, bank shares lead decline By Alastair Sharp TORONTO, March 13 (Reuters) - Canada's main stock index fell sharply on Wednesday, coming off the 19-month high it reached on Tuesday, as investors retreated from heavyweight energy, bank and mining stocks. The resources-rich index posted a broad decline despite buoyant commodity prices, and some of the country's big banks also weighed heavily. Royal Bank of Canada was the single biggest weight, down 0.8 percent at C$61.98, and Bank of Nova Scotia fell 0.6 percent to C$60.26. "We've come a long way. The stock market can't go up every single day," said Craig Fehr, Canadian market strategist at Edward Jones in St. Louis, Missouri. "It's reasonable for investors to start to expect a little more volatility or potentially even a pullback in the near term," he said. The Toronto Stock Exchange's S&P/TSX composite index was down 81.95 points, or 0.64 percent, at 12,796.63 at mid-morning. The TSX has risen roughly 9 percent since a mid-November trough, and hit a 19-month high on Tuesday, though it has underperformed U.S. indexes over that period. "The energy stocks in particular have done very well in the last two weeks," said John Kinsey, portfolio manager at Caldwell Securities. "The materials not so much ... gold stocks are still languishing even though the metal has been coming up for about the last week." Goldcorp Inc fell 1.5 percent to C$33.40 and Teck Resources Ltd lost 2 percent to C$30.98.