TORONTO (Reuters) - Toronto's main stock index fell sharply yesterday after US Federal Reserve Chairman Ben Bernanke said the US economy faces "unusually uncertain" prospects.

Bernanke said policymakers believe the US economy is still on the path to recovery, but that the Fed is ready to take further steps to bolster growth if needed.

His remarks to the US Senate banking committee added to investor jitters about a sluggish economic recovery, helping to push down North American equities.

In Canada, big names on the downside included Royal Bank of Canada, off 2.9 percent at C$52.00, and Toronto-Dominion Bank , down 1.6 percent at C$70.55.

"It's all about the outlook being 'unusually uncertain'. This is not the environment to put risk on," said Francis Campeau, broker at MF Global Canada in Montreal.

"It's a perfect environment to duck and cover."

Suncor Energy was down 1.8 percent at C$32.54, and Canadian Natural Resources fell 1.6 percent to C$35.92 as oil prices fell, due in part to data showing US crude inventories rose unexpectedly last week.

The Toronto Stock Exchange's S&P/TSX composite index finished the session down 116.55 points, or one percent, at 11,513.33. Nine of the index's 10 main groups skidded.

The index's heavily weighted energy and financials sectors led the slide, down 1.2 percent and 1.9 percent, respectively. The lone sector in the black was consumer staples, up 0.3 percent.

Encana Corp., Canada's biggest natural gas producer, was down 4.6 percent at C$32.90 after reporting a quarterly loss, hurt partly by commodity hedging.

"Encana coming out this morning with not so great news so I think that really took the wind out of the TSX's sail," said Serge Pepin, head of investments at BMO Investments Inc.

As well, Mr. Pepin said a robust quarterly report from Apple Inc. hurt Research In Motion which was off 3.1 percent at C$55.94.

The blue chip S&P/TSX 60 index closed 8.61 points, or 1.26 percent, lower at 673.15.

Teck Resources rose 2.4 percent to C$35.14, and Bombardier Inc. rose 2.8 percent to C$4.78.