Canada's main stock index posted its biggest advance in three months on Tuesday, led by financial sector gains, while higher commodity prices helped boost energy and gold mining shares.

The Toronto Stock Exchange's S&P/TSX composite index closed up 103.11 points, or 0.69 per cent, at 15,143.41, its biggest gain since June 1.

Gains for the index came as investor concerns about U.S. tensions with North Korea eased and the financial impact from Hurricane Irma appeared less severe than feared, helping to push stocks on Wall Street to a record high.

"There has been such a lag in Canada that there is definitely a catch-up trade to be had here," said Mike Archibald, associate portfolio manager at AGF Investments. "It is just a case of can we get a catalyst to get it moving."

After rallying 17.5 per cent in 2016, the TSX has dipped 0.9 per cent this year. That compares with a 11.5 per cent gain this year for the S&P 500.

One drag on Canada's market in 2017 has been lower oil prices. But oil rose on Tuesday after OPEC forecast higher demand in 2018.

U.S. crude oil prices settled 16 cents higher at US$48.23 a barrel, while the energy group, which accounts for 20 per cent of the weight of the TSX, gained 1.4 per cent.

Nuvista Energy Ltd jumped 4.8 per cent to $6.84 after it reaffirmed its 2017 guidance.

Potash producer Agrium Inc (AGU.TO) edged 0.1 per cent higher to $124.44 and Potash Corp of Saskatchewan (POT.TO) rose 0.1 per cent to $22.20 after Canada's Competition Bureau said it will not challenge their proposed merger.

Eight of the index's 10 main groups ended higher.

The materials group, which includes precious and base metals miners and fertilizer companies, added 0.8 per cent, helped by gains for gold miners as the precious metal bounced up from the lowest level in more than a week.

The heavyweight financials group gained 0.7 per cent, with Royal Bank of Canada (RY.TO), the country's largest bank by market capitalization, gaining 0.8 per cent to $91.82 and insurer Manulife Financial Corp (MFC.TO) adding 1.5 per cent to $24.92.

Home Capital's (HCG.TO) shareholders rejected a proposal for Warren Buffett's Berkshire Hathaway to raise its stake in the company, voting against the board's recommendation in a third defeat for the U.S. billionaire this year.

Home Capital's shares climbed 1.8 per cent to $14.33.