TORONTO (Reuters) - The Toronto Stock Exchange's main index finished lower yesterday as strength in resources was undercut by losses in the banking sector amid nagging worries over the continuing impact of the credit crunch.

The financial group shed 2.5 percent. The sector faces a number of ongoing headwinds, including fears of more writedowns related to the troubled US housing market, jitters over the health of US bond insurers, as well as pessimism over financial results.

Bank of Montreal gave up C$1.34, or 2.7 percent, to C$48.36, caught up in recent downward pressure after it warned it might have to write down its remaining C$495 million exposure to two troubled asset-backed commercial paper trusts.

Bank of Montreal, Canada's fourth-largest bank, is set to report quarter results today. Bank of Nova Scotia, which is also expected to report results today, was down C$1.29, or 2.7 percent, to C$46.50.

The S&P/TSX composite index closed down 38.31 points, or 0.28 percent, at 13,544.38 with six of its 10 main groups in negative territory.

In a choppy session, the index fell more than 100 points in the late afternoon.

Also weighing on the index, BlackBerry-maker Research In Motion slid C$3.52, or 3.4 percent, to C$99.01, helping to pull the tech sector down two percent. Nortel Networks was down 54 Canadian cents, or 6.4 percent, at C$7.94.

On the upside, shares in gold producers provided the Toronto benchmark with a bright spot. The sub-index surged 3.8 percent as bullion prices set a record high for the fourth day in a row, moving toward $1,000 an ounce. Spot gold climbed as high as $989.30 before easing to $981.20.

Barrick Gold jumped C$1.72, or 3.4 percent, to C$52.92, and Kinross Gold was up C$1.55, or 6.4 percent, to C$25.90.

The larger materials group added 1.9 percent, with Teck Cominco Ltd.'s more heavily traded class B shares rose C$1.70, or 4.3 percent, to C$40.97 after the company announced a new copper resource at its Quebrada Blanca property in northern Chile.

The heavyweight energy sector rose 0.6 percent as crude also hit a new high on expectations that OPEC will not raise oil production at its meeting this week. Oil jumped to a high of $103.95 a barrel and later settled at $102.45.

Suncor Energy gained C$2.37, or 2.3 percent, to C$103.87, and Canadian Oil Sands Trust advanced C$1.48, or 3.6 percent, to C$43.18.