The Nasdaq Composite Index has lost 38 points at 2,344. And the Standard-and Poor's 500 Stock Index is down 26 at 1,354.
Trading on the New York Stock Exchange during the first two hours totaled 1.4 billion shares. Volume on the Nasdaq Market came to 828 million shares.
Stocks are staging declines for a second straight session. Investors were treated to a negative surprise before the opening bell when the Institute for Supply Management released its service sector index early, showing a sharp decline.
The index dropped to 44.6 last month, indicating contraction in the non-manufacturing portion of the economy. It marks the first such contraction in more than four and a half years. Analysts had been looking for growth.
