NEW YORK (AFP) - US stocks sank more than 1 per cent at the open on Thursday, hit by a China-driven global markets sell-off and the Federal Reserve's announcement that it could begin slowing its "quantitative easing" stimulus this year.

Five minutes into trade, the Dow Jones Industrial Average was down 159.54 points (1.06 per cent) at 14,952.65. The broad-based S&P 500 fell 19.45 (1.19 per cent) to 1,609.48, while the tech-rich Nasdaq Composite Index tumbled 43.1 (1.25 per cent) to 3,400.1.