United Parcel Service, General Electric and others issued disappointing results or forecasts.
The Standard & Poor's 500 index fell seven points, or 0.4 per cent, to close at 1,838 Friday.
The Nasdaq fell 21 points, or 0.5 per cent, to 4,197.
The Dow Jones industrial average rose, but mostly because of large gains in American Express and Visa.
The Dow rose 41 points, or 0.3 per cent, to 16,458. Without the gains from Amex and Visa, the average would have been much lower.
Amex reported late Thursday that its income more than doubled in the fourth quarter.
Student loan company SLM fell 10 per cent after its earnings missed expectations. The stock fell the most in the S&P 500 index.