TORONTO - Canada's main stock index posted a triple-digit advance to start the week as the price of gold soared by nearly US$50, boosting the mining-heavy materials sector.

The S&P/TSX composite index rose 141.51 points to 16,656.12.

“We have a strong showing in precious metals,” said Anish Chopra, managing director with Portfolio Management Corp.

The materials sector, which includes the major gold miners, led the strong performance Monday with a gain of 5.32 per cent.

That surge came as the price of the precious metal soared. The December gold contract added US$48.90 to US$1,998.70 an ounce.

The gains come after Warren Buffett's Berkshire Hathaway Inc. reported it purchased shares of Toronto-based Barrick Gold Corp., said Chopra. Barrick's share price jumped more than 11 per cent, ending the day up $4.05 at $39.84 on the Toronto Stock Exchange.

Buffett and his company generally haven't invested in gold or gold miners, said Chopra.

“Investors are surprised, positively, by the news that Berkshire Hathaway took a position in Barrick Gold. So investors are reading that as a positive onto the gold mining sector and the gold sector in general,” he said.

The news also drove the mining sector south of the border, said Chopra, though he noted it has a smaller presence on U.S. markets than the resource-heavy TSX.

In New York, the Dow Jones industrial average fell 86.11 points to 27,844.91. The S&P 500 index gained 9.14 points to 3,381.99, while the Nasdaq composite added 110.42 points to 11,129.73.

The S&P 500 continues to teeter near its all-time closing high of 3,386.15, set in February.

The Canadian dollar traded for 75.72 cents US compared with 75.47 cents US on Friday.

In commodities trading, the September crude contract gained 88 cents to US$42.89 per barrel and the September natural gas contract lost nearly two cents to roughly US$2.34 per mmBTU. The September copper contract advanced four cents to US$2.90 a pound.