TORONTO (Reuters) - Toronto's main stock index closed sharply higher yesterday as investors raced back into equities after a string of sell-offs had left the TSX at its lowest level in two weeks.

The heavyweight materials sector, which had spearheaded the index's steep slide in the previous session, rebounded to lead yesterday's rally. The energy group also fuelled the gain.

Toronto's key index tumbled more than three percent on Monday to erase all of the gains it had made since the start of the year. Last week it was up 5.76 percent for the year.

"Energy and commodity stocks did quite well and that's helped prop up the market," said Elvis Picardo, analyst and strategist at Global Securities in Vancouver.

"So money is starting to come back to energy and materials because stocks in those sectors were hurt disproportionately during the market meltdown."

The Toronto Stock Exchange's S&P/TSX composite index rallied 168.22 points, or 1.91 percent, to close at 8,961.55. That was 24 points off the session high of 8,986.15 the index reached shortly after midday.

A big boost to the index came from the materials group as the same big-name gold mining shares that led recent declines rebounded as investors felt the downward moves were overdone.

The materials group, which accounts for about 20 percent of the overall Toronto index, led all sectors with a gain of 3.91 percent. The energy group followed with a 2.67 percent gain.

Shares of Barrick Gold Corp, the biggest contributor to the index's gain, rose 5 percent to C$39.98, while Goldcorp shares jumped 3.65 percent to C$31.49.

Yamana Gold, which said it is back in the hunt for acquisitions, also chipped in as its shares rallied 2.4 percent to C$7.95.