(Adds details, comments, official closing data)
By Wojtek Dabrowski
TORONTO, March 31 (Reuters) - The Toronto Stock Exchange's main index finished Monday's scattershot session in positive territory after a series of wild swings that saw the benchmark jump, plunge and surge again as volatility ruled.
The key S&P/TSX composite index .GSPTSE rose 116.34 points, or 0.88 percent, to close at 13,350.13. Earlier, the index set the day's low at 13,131.08.
"I think what investors are trying to do is they're trying to see some daylight," said Adrian Mastracci, portfolio manager at KCM Wealth Management Inc, in Vancouver, British Columbia. "They're not really finding it yet."
All but one of the 10 main index groups ended higher, including the key energy and financials groups, which added 0.68 percent and 3.34 percent respectively.
The materials group was the sole decliner, shedding 1.67 percent.
The S&P/TSX 60 index of large Canadian companies added 6.92 points to end at 783.44.
The see-saw session began with a rise of more than 100 points, but by 3 p.m. (1900 GMT) the index had plunged by the same amount. The last hour saw another change in direction, leading to the positive finish.
There was relatively little corporate news or other data to sway investor sentiment on Monday aside from U.S. Treasury Secretary Henry Paulson's proposal to overhaul that country's financial regulatory landscape.
That could have helped steady some nerves and aided the rally in financial shares, said Ian Nakamoto, director of research at MacDougall, MacDougall & MacTier.
As well, the session is the last of the quarter, and fund managers often tweak the contents of their portfolios ahead of a quarter's end in a practice sometimes referred to as "window-dressing", Mastracci said.
This week also marks the beginning of earnings season, with fitness apparel retailer Lululemon Athletica LLL.TO and BlackBerry maker Research In Motion RIM.TO among major names slated to report.
Nakamoto said he expects corporate earnings to be weak and financial outlooks to be muted, with only a few bright spots -- RIM among them.
"I think if anything, RIM's earnings are going to stand in contrast to what most companies are going to report," he said, adding that steel companies and agricultural names could also deliver positive results.
RIM, one of the Toronto market's most volatile stocks, ended the day lower by C$1.58 at C$115.49.
Mastracci also said he expects "lesser" earnings from corporate Canada and said he is staying out of shares for the time being.
"I'm not buying into equities yet," he said. "Any new money going in for the moment is still going into fixed income, so I'm playing the cautious game for now."
In the United States, the Dow Jones industrial average .DJI finished higher, adding 46.49 points, or 0.38 percent, to close at 12,262.89. The Nasdaq rose 17.92 points to end at 2,279.10.
$1=$1.03 Canadian Reporting by Wojtek Dabrowski; Editing by Peter Galloway