A weak batch of earnings reports is sending the stock market slightly lower in early trading.

Harman International, which makes audio systems for cars, Varian Medical Systems and Celgene all dropped in early trading Thursday after their revenue fell short of analysts' estimates.

The Dow Jones industrial average lost 13 points, or 0.1 percent, to at 18,024 as of 9:35 a.m. Eastern time.

The Standard & Poor's 500 index fell two points, or 0.1 percent, to 2,104. The Nasdaq composite fell 12 points, or 0.3 percent, to 5,011.

Bond prices fell after some mostly encouraging news on the U.S. economy, including a drop in claims for unemployment benefits.

The yield on the 10-year Treasury note rose to 2.08 percent.