Wall Street dipped as investors fretted over the effectiveness of a new US economic stimulus law and two automakers raced to submit restructuring plans for their survival.

The Dow Jones Industrial Average plunged 297.41 points (3.79 per cent) to 7,553.00 at the closing bell. The tech-dominated Nasdaq dropped 63.70 points (4.15 per cent) to 1,470.66 and the broad-market Standard & Poor's 500 index retreated 37.53 points (4.54 per cent) to 789.31, according to preliminary closing figures.