The Dow Jones industrial average slipped to 14,550.35, losing 111.66 points, or 0.76 percent, in late afternoon trading.
The Nasdaq composite lost 36.26 points, or 1.11 percent, to 3,218.60.
The Standard and Poor's 500 dropped 16.56 points, or 1.05 percent, to 1,553.69.
Payroll processor ADP said private-sector employment rose by 158,000 jobs from February to March, less than the 251,000 jobs analysts had anticipated.
Mark Zandi, chief economist of Moody's Analytics, said, "Job growth moderated in March. ... The job market continues to improve, but in fits and starts."
The 10-year U.S. treasury note was yielding 1.813 percent in midday trading.
On the New York Stock Exchange, the total share volume was 4.04 billion shares. Decliners outpaced gainers 3.4 billion shares to 583 million shares.
Against the dollar, the euro was $1.2848 from $1.2822 Tuesday. Against the yen, the dollar traded at 93 from 93.36 yen Tuesday.
In Tokyo, the Nikkei 225 index closed at 12,362.20, adding 358.77 points, or 2.99 percent.
In London, the FTSE 100 lost 70.38 points, or 1.08 percent, closing at 6,420.28.