Canada's main stock index was down more than 300 points in broad-based decline as commodity prices also fell and U.S. stock markets pulled back.
The S&P/TSX composite index was down 305.55 points at 18,773.09.
In New York, the Dow Jones industrial average was down 346.94 points at 30,682.37. The S&P 500 index was down 45.85 points at 3,772.98, while the Nasdaq composite was down 166.37 points at 11,011.52.
The Canadian dollar traded for 77.59 cents US compared with 77.65 cents US on Wednesday.
The August crude contract was down US$4.31 at US$105.47 per barrel and the August natural gas contract was down 42 cents at US$6.08 per mmBTU.
The August gold contract was down US$9.00 at US$1,808.50 an ounce and the September copper contract was down nine cents at US$3.69 a pound.