(Adds market reaction, commodity prices, details)
* TSX up 135.11 points, or 1 percent, at 13,687.31
* Seven of the TSX's 10 main groups are down
TORONTO, Oct 6 (Reuters) - Canada's main stock index rallied on Tuesday, with heavily weighted financials and resource stocks carrying most of the gains on the back of higher commodity prices.
Oil and gas stocks were bolstered by a more than 3 percent rise in crude prices, while firmer gold prices contributed to gains in the materials group, home to mining and other resource companies.
The most influential mover on the index was Canadian Natural Resources, which rose 3.6 percent to C$29.20. Crescent Point Energy surged 10.7 percent to C$19.50, and energy stocks climbed 3.6 percent overall.
At 11:30 a.m. EDT (1530 GMT), the Toronto Stock Exchange's S&P/TSX composite index was up 135.11 points, or 1 percent, at 13,687.31.
Only three of the 10 main sectors - financials, energy and materials - were in positive territory, but they account for roughly two-thirds of the index's weight.
Advancing issues outnumbered declining ones on the TSX, for a 1.88-to-1 ratio on the upside.
Oil prices headed for the first three-day gain in five weeks amid signs that the world's largest crude producers might act jointly to support prices, which have halved over the past year. U.S. crude was up 3.9 percent at $48.04 a barrel, while Brent crude added 4.3 percent to $51.35.
Barrick Gold Corp was a key gainer among materials, jumping 7.6 percent to C$9.64. The sector rallied 3.8 percent.
Gold prices rose 1.1 percent to $1,150 an ounce as the U.S. dollar softened on the back of disappointing economic data that could push the Federal Reserve's next rate hike further away.
Financials, home to Canada's largest banks, rose 0.8 percent. Royal Bank of Canada rose 1.0 percent to C$73.28.
In corporate news, miner First Quantum Minerals said late on Monday that it had revised its deal with Franco-Nevada Corp for its flagship copper-gold Cobre Panama project in Central America.
Under the new terms, royalty firm Franco-Nevada will have to pay an initial contribution of $330 million to $340 million to First Quantum in October. Shares of First Quantum soared 19.8 percent to C$7.42. (Reporting by Solarina Ho; Editing by Lisa Von Ahn)