Poor earnings reports from three stocks in the Dow Jones industrial average - Microsoft, General Electric and McDonald's - are sending the Dow down more than 100 points, marking a weak end to an otherwise strong week in the stock market.

All three stocks fell about 3 percent, the most among the 30 stocks in the Dow.

In midday trading Friday the Dow was down 133 points at 13,415.

The Standard & Poor's 500 sank 14 points to 1,443 and the Nasdaq composite dropped 43 points to 3,029.

McDonald's profit sank as a strong dollar hurt international results, which account for two-thirds of its business.

Microsoft's income fell 22 percent as PC sales took a dive and troubles in Europe took their toll. General Electric's revenue missed Wall Street's expectations.