* TSX down 56.66 points, or 0.38 percent, at 14,999.33
* Nine of the TSX's 10 main groups were lower
* Toromont surges 12.4 percent on plans to buy Hewitt Group (Updates prices)
TORONTO, Aug 28 (Reuters) - Canada's main stock index fell on Monday as a decline in U.S. crude oil prices following the impact of Tropical Storm Harvey weighed on shares of companies in the energy sector.
U.S. crude oil prices declined 1.4 percent after Tropical Storm Harvey inflicted damage along the U.S. Gulf Coast during the weekend. the heavily weighted energy sector, Canadian Natural Resources Ltd CNQ.TO fell 0.7 percent to C$38.36, and Suncor Energy Inc SU.TO slipped 0.3 percent to C$39.08.
Overall, the energy group shed 0.7 percent.
The financial services sector lost 0.5 percent. Royal Bank of Canada RY.TO was down 0.5 percent to C$92.79, and Toronto Dominion Bank TD.TO retreated 0.5 percent to C$64.52.
The Toronto Stock Exchange's S&P/TSX composite index .GSPTSE fell 56.66 points, or 0.38 percent, to 14,999.33. Nine of the TSX's 10 main groups were lower.
Shares of Toromont Industries Ltd TIH.TO jumped 12.4 percent to C$50.47 after the company said it would buy privately held Hewitt Group for about C$1.02 billion ($818 million) in cash and shares to expand its network of heavy equipment dealers in eastern Canada.