North American stocks opened sharply lower, with the benchmark Dow Jones Industrial average losing 270.53 points, or 2.4 per cent, within minutes of the start of trading.
The S&P 500 sank 28.56 points, or 2.4 per cent.
Toronto's S&P/TSX Composite Index lost 186.74 points, or 1.5 per cent.
At the root of the decline were fears the euro zone's sovereign debt crisis was worsening and the U.S. economy was slipping back into a recession.
Oil traded $2.42 (U.S.) lower at $84.03 a barrel.
Gold rose $15.20 to $1,892.10 an ounce.