Stocks ended the worst week in a year as the clock runs down on Washington leaders to reach an agreement before Uncle Sam loses the ability to borrow.

The Dow Jones industrial average dropped 96.87 points, or 0.79 percent, to 12,143.24. The Standard & Poor's 500 Index fell 8.39 points, or 0.65 percent, to 1,292.28. The Nasdaq Composite Index lost 9.87 points, or 0.36 percent, to 2,756.38.

(Reporting by Chuck Mikolajczak; Editing by Kenneth Barry)