TORONTO (Reuters) - The main index of the Toronto Stock Exchange sagged yesterday as strong earnings reports from two of Canada's biggest banks failed to attract investors, who appeared more interested in taking profits.

The S&P/TSX composite index fell 45.49 points, or 0.34 percent, to close at 13,444.63. The drop followed a 225-point jump booked during Wednesday's session.

"I think this is basically some profit-taking following the rise yesterday," Elvis Picardo, investment strategist at Northern Securities Inc, said of the market.

The bluechip S&P/TSX 60 index dropped 2.86 points to close at 781.08.

About 246.3 million shares worth C$4.62 billion changed hands, according to latest available data. There were 709 advancers and 813 decliners.

All but one of the benchmark's 10 main subgroups tracked lower, including energy and materials, which fell 0.3 percent and 0.25 percent respectively. Utilities was the day's lone advancing sector, adding one percent.

Financials slid lower as well, even as investors digested robust profit reports from both Canadian Imperial Bank of Commerce and National Bank of Canada. The sector shed 0.37 percent.

CIBC added 95 Canadian cents, or one percent, to close at C$94.92, after it raised its dividend and posted a jump in third-quarter earnings.

National Bank sagged, however, as it told investors they would have to wait to learn the financial impact of its C$2 billion purchase of embattled asset-backed commercial paper investments. Its shares finished the day 73 Canadian cents - or 1.3 percent - lower, at C$55.96, despite better than expected profits.

The shares of BlackBerry maker Research In Motion Ltd gained early in the day as rumors resurfaced that software giant Microsoft Corp could buy the company.

By day's end, RIM was up 91 Canadian cents, or one percent, at C$87.71 after retreating from a high of C$89.68.

The main Canadian stock index has zig-zagged this week as investors weighed the potential fallout from a liquidity crisis that has threatened world credit markets in recent days.

Adrian Mastracci, portfolio manager at KCM Wealth Management Inc, said some investors are still coming to grips with the Toronto market's volatility.

"Those that have been through this before know that this, too, shall pass one day." Picardo said the composite is having a difficult time breaking the 13,500 barrier once again.

"That was a level that provided decent support on the downside for a couple of months," he said. "But now, conversely, it seems to be quite a strong resistance point."