Canada's main stock index was down nearly 500 points in early trading as the price of oil fell below US$80 a barrel and U.S. stock markets also fell deep into the red.
The S&P/TSX composite index was down 479.71 points at 18,522.97.
In New York, the Dow Jones industrial average was down 375.12 points at 29,701.56. The S&P 500 index was down 61.51 points at 3,696.48, while the Nasdaq composite was down 197.31 points at 10,869.50.
The Canadian dollar traded for 73.73 cents US compared with 74.18 cents US on Thursday.
The November crude contract was down US$4.21 at US$79.28 per barrel and the November natural gas contract was down 30 cents at US$6.90 per mmBTU.
The December gold contract was down US$24.40 at US$1,656.70 an ounce and the December copper contract was down 12 cents at US$3.35 a pound.