Canada's main stock index was down more than 200 points in late-morning trading in a broad-based decline, while U.S. stock markets also fell.
The S&P/TSX composite index was down 271.77 points at 18,377.15.
In New York, the Dow Jones industrial average was down 484.95 points at 29,198.79. The S&P 500 index was down 81.16 points at 3,637.88, while the Nasdaq composite was down 340.17 points at 10,711.47.
The Canadian dollar traded for 73.01 cents US compared with 73.21 cents US on Wednesday.
The November crude contract was up 17 cents at US$82.32 per barrel and the November natural gas contract was down 25 cents at US$6.71 per mmBTU.
The December gold contract was down US$6.00 at US$1,664.00 an ounce and the December copper contract was up four cents at US$3.40 a pound.