US stocks ended a miserable week with steep losses as worries about growth in the United States, China and Europe eclipsed a solid start to the corporate earnings season.

All three main stock indices lost more than 1 per cent on Friday, snapping a two-day rally as investors fretted about Spain's rocky finances amid spiking borrowing costs.

The Dow Jones Industrial Average finished at 12,849.59 points, down 1.61 per cent on the week.

The Standard & Poor's 500 index, a broad measure of the markets, shed 2 per cent for the week at 1370.26. That was its biggest weekly decline so far this year.