Losses in base metal and technology stocks helped lead a broad-based decline as Canada's main stock index fell nearly 300 points in late-morning trading and U.S. stock markets also tumbled.
The S&P/TSX composite index was down 285.36 points at 19,929.33.
In New York, the Dow Jones industrial average was down 190.40 points at 34,250.48. The S&P 500 index was down 46.42 points at 4,355.78, while the Nasdaq composite was down 158.60 points at 13,310.53.
The Canadian dollar traded for 74.18 cents US compared with 74.50 cents US on Wednesday.
The November crude contract was up 69 cents at US$90.35 per barrel and the November natural gas contract was down two cents at US$2.91 per mmBTU.
The December gold contract was down US$27.10 at US$1,940.00 an ounce and the December copper contract was down nine cents at US$3.68 a pound.