Stocks opened lower on Friday as disappointing results from Microsoft Corp and American Express Co curbed sentiment a day after a rally took the Dow industrials <.DJI> above the key 9,000 mark.

The Dow Jones industrial average dropped 35.00 points, or 0.39 percent, to 9,034.29. The Standard & Poor's 500 Index <.SPX> shed 5.61 points, or 0.57 percent, to 970.68. The Nasdaq Composite Index <.IXIC> slid 28.29 points, or 1.43 percent, to 1,945.31.

(Reporting by Chuck Mikolajczak; editing by Jeffrey Benkoe)