TORONTO (Reuters) - Toronto's main stock index snapped a three-day slide yesterday, climbing nearly 140 points as the big materials, energy and financials sectors led a broadbased rally.

The materials and energy groups began the session lower, spurred by soft commodity prices. But both eventually gained momentum to the upside, recovering a portion of Wednesday's steep losses.

The energy sector finished ahead 1.52 percent as crude prices climbed on renewed economic optimism.

Materials gained 1.41 percent, backed by strength in gold in a mixed session.

"Golds were strong, gathered strength all day. They were one of the better performing groups," said John Ing, president of Maison Placements Canada.

"Overall it's just a strong day after yesterday's correction."

Ing added that today's trading will likely be "constrained" as market players gear up for a long weekend with Victoria Day in Canada on Monday.

Financials rose 1.66 percent after retreating for three straight sessions in what analysts called a "consolidation" phase. The strength was widespread across eight of the TSX's 10 main sectors, though most of the influential movers were from the index's big three groups.

Royal Bank of Canada led the pack, up 2.64 percent at C$42.35, followed by Potash Corp of Saskatchewan, which was up 4.56 percent at C$126.01. Suncor Energy gained 2.79 percent to C$34.64.

The Toronto Stock Exchange S&P/TSX composite index closed up 139.69 points, or 1.44 percent, at 9,849.20.

The rebound comes after the TSX posted its first three-day retreat in more than a month. Entering the session, the index was up about 30 percent on a run of weekly gains, after hitting a five-year low in March.

Some consumer stocks were active, triggered by a higher than expected profit at retailer Canadian Tire Corp and a positive outlook from Gildan Activewear .

Canadian Tire rose six percent to C$48.20, while Gildan climbed 24.1 percent to C$15.65.

Meanwhile, Forzani Group rose 7.36 percent to C$14.01, as the sporting-goods retailer recommended that shareholders oppose a bid from a hedge fund attempting to nominate its own members to the board.