Energy shares extended recent losses as oil prices settled down more than four per cent after weak US economic data spurred worries over oil demand. The Dow Jones industrial average fell 106.38 points, or 0.61 per cent, to 17,320.71, the S&P 500 lost 18.6 points, or 0.92 per cent, to 1,992.67 and the Nasdaq Composite dropped 68.50 points, or 1.48 per cent, to 4,570.82.
The S&P is now down 4.7 per cent from its 29 December record high.
Adding to volatility, the Swiss National Bank scrapped its cap on the franc currency in a surprise move. US-traded Swiss stocks climbed. Credit Suisse was up 1.8 per cent at $23.22 and Novartis jumped 3.9 per cent to $100.58.