Canada's main stock index edged down Wednesday after the Bank of Canada surprised many with an interest rate increase, with the move cutting into earlier gains for energy stocks as oil prices rose.

The Toronto Stock Exchange's benchmark Standard & Poor's/TSX Composite Index declined 30.32 points, or 0.2 percent, to finish the day at 15,059.83. Eight of the index's 10 main groups closed lower.

The most influential gainers included Alimentation Couche Tard, which jumped 2.2 percent to 60.76 Canadian dollars after the convenience store operator reported better-than-expected quarterly earnings.

The energy group trimmed sharper gains before the rate hike announcement, with Canadian Natural Resources up 1.4 percent to 39.83 Canadian dollars and Encana Corp also up 1.4 percent to 11.69 Canadian dollars.

Pipeline company Enbridge rose 0.4 percent to 49.96 Canadian dollars and rival TransCanada Corp added 0.6 percent to 62.76 Canadian dollars.

Hudson's Bay Co fell at the open before paring those losses to last trade down 1.2 percent at 11.13 Canadian dollars. The department store behemoth reported a bigger-than-forecast quarterly loss after the bell on Tuesday.

The Canadian dollar leaped 0.97 cents to 0.81.82 U.S. dollar while gold prices jumped 50 cents to 1,343.00 U.S. dollars an ounce.