The index has rebounded more than 15 percent from an almost 3-1/2-year low in January, but has been unable to sustain moves since mid-March above its 200-day moving average as the rally in commodity prices ran out of steam.

"Like the cold weather we are having on Bay Street, the TSX (Toronto Stock Exchange) may be set for some cooling as well," said Stan Wong, Director of Wealth Management at ScotiaMcLeod, referring to the unseasonably cold weather that has gripped Toronto's financial district.

The most influential movers on the index included Brookfield Asset Management (>> Brookfield Asset Management Inc), which fell 4.8 percent to C$42.91, while Manulife Financial Corp (>> Manulife Financial Corp.) was down 1.5 percent at C$17.99. The overall financial services group fell 0.4 percent.

A usually cautious Federal Reserve official delivered a surprisingly confident message, saying the Fed will likely raise interest rates before markets currently expect given economic risks have faded.

The materials group, which includes precious and base metals miners and fertilizer companies, lost 2 percent, including weakening in the shares of fertilizer companies.

Potash Corp (>> Potash Corporation of Saskatchewan Inc) fell 3.4 percent to C$21.42 after CIBC downgraded its recommendation on the stock and cut its price target, while rival Agrium Inc (>> Agrium Inc.) was down 1.3 percent at C$113.76.

Mining stocks dragged as spot gold fell 0.5 percent, while copper touched its lowest in a month and nickel slipped to its weakest in six weeks.

The Toronto Stock Exchange's S&P/TSX composite index <.GSPTSE> closed down 104.29 points, or 0.78 percent, at 13,336.15. Nine of the index's 10 main groups ended lower.

"Investors are taking their bets off the table" amid concern about the strength of China's economy and retracement in the price of crude oil, said Wong.

The energy group fell 1.7 percent, including a 1.9 percent decline in the shares of Suncor Energy Inc (>> Suncor Energy Inc.) to C$35.33.

U.S. crude prices settled at $35.70 a barrel, down nearly 3 percent, as prospects of top exporters agreeing to curb chronic oversupply faded.

The lone sector to advance was telecoms. It rose 0.3 percent as investors sought refuge in high-dividend defensive names, a preference Wong expects to continue in the near term.

(Additional reporting by Alastair Sharp; Editing by James Dalgleish)

By Fergal Smith