TORONTO (Reuters) - The Toronto Stock Exchange’s main index ended higher, snapping a two-day losing streak, as shares of oil and gas companies rose on a rally in oil prices, while earnings strength from Nova Chemicals helped to boost materials issues.The S&P/TSX composite index closed up 82.52 points, or 0.6 percent, at 13,672.85.

“Almost 50 percent of the TSX is commodity-related and they are very volatile,” said John Kinsey, portfolio manager at Caldwell Securities. “So as the commodities go, so goes our index.”

Seven of the TSX index’s 10 main groups were higher, led by a 1 percent jump in the energy sector as US crude oil rose $1.26 to $65.84 a barrel after weekly US data showed a bigger-than-expected drop in gasoline stocks ahead of the summer driving season.

Oil has also been boosted by refinery problems and maintenance, said Rob Moss, oil and gas analyst at Acumen Capital Partners, in Calgary, Alberta.

“There’s definitely some issues on the refinery side,” he said. “It is refinery maintenance time of the year in anticipation of creating inventories for summer driving.”

Among oil and gas stocks, EnCana was up 22 Canadian cents, or 0.4 percent, at C$60.32 after it reported higher-than-expected quarterly operating earnings.

Suncor Energy rose C$1.41, or 1.6 percent, to C$91.45, while Canadian Oil Sands Trust rose C$1.19, or four percent, to C$30.18.

Raw plastics maker Nova Chemicals soared C$3.72, or 11.1 percent, to C$37.40 after it said it swung to a profit in the first quarter on improved margins and cost reductions.

The results helped to boost the resource-laden materials group, which ended up 0.9 percent.