The Toronto Stock Exchange's S&P/TSX composite index <.GSPTSE> ended down 48.49 points, or 0.35 percent, at 13,661.82, with resource stocks particularly hard hit.

The materials group fell 1.4 percent and energy stocks slipped 0.6 percent, as gold slid to a one-month low and oil fell 4 percent. [GOL/] [O/R]

"The market's reacted as if the Fed could raise rates in December, and as a result you saw a sell-off in both the U.S. market and in the Canadian market, you saw a sell-off in gold, you saw the sell-off in energy prices," said Macan Nia, a director for capital markets and strategy at Manulife Asset Management.

Valeant Pharmaceuticals International Inc (>> Valeant Pharmaceuticals Intl Inc) fell 5.1 percent to C$121.20 as a U.S. Senate panel launched a probe into drug pricing, for which the company has come under heavy scrutiny.

On the positive side, ProMetic Life Sciences Inc (>> ProMetic Life Sciences Inc.) jumped 9.5 percent to C$2.54 after it said its plasminogen replacement therapy, currently going through U.S. clinical trials, had been successfully used to treat an infant in Germany.

Technology company CGI Group Inc (>> CGI Group Inc) gained 4.3 percent to close at C$53.03 after hitting its highest since May 20.

Decliners outnumbered advancing issues by 143 to 93, for a 1.54-to-1 ratio on the downside.

(Reporting by Alastair Sharp; Editing by Jeffrey Benkoe and James Dalgleish)

By Alastair Sharp