New York - Wall Street stocks tumbled into negative territory early on Wednesday after the monthly ISM report showed slowing growth in the US services sector in January.
About 40 minutes into trade, the Dow Jones Industrial Average was at 16 096.32, down 57.22 points (0.35%).
The broad-based S&P 500 fell 13.12 (0.69%) to 1 889.91, while the tech-rich Nasdaq Composite Index dropped 48.46 (1.07%) to 4 468.48.
The Institute for Supply Management purchasing managers index for non-manufacturing activity fell 2.3 points to 53.5 in January, showing the largest sector of the economy expanding at a slower pace than before.
Earlier payrolls firm ADP said private-sector employers added 205 000 jobs in January, a bit more than the 190 000 expected by analysts. The report came two days ahead of the January jobs report from the US Department of Labor.
Dow member Merck fell 2.2% after it projected 2016 earnings of $3.60-$3.75 per share. Analysts have forecast the drugmaker would earn $3.72 a share.
General Motors fell 2.8% despite reporting fourth-quarter earnings that translated into $1.39, 18 cents above analyst expectations. Barclays said investors worry the booming US auto market has peaked.
Yahoo slumped 8.3% as it announced it was cutting 15% of its workforce and suggested it could seek a deal to sell or merge the company.
Chipotle Mexican Grill sank 7.3% as it reported a 44% decline in fourth-quarter earnings to $67.9m after a pair of E.coli outbreaks depressed sales. Investment bank Jefferies warned of a "possible long road to recovery."
Comcast rose 2.3% after it hiked its dividend by 10%and authorised an additional $10bn in share repurchases. Net income for the fourth quarter rose 2.4% to $2bn.
US home improvement retailer Lowe's fell 6.5% on news it will acquire Canadian rival Rona for about $2.3bn.
Food company Mondelez International fell 5.1% after reporting a $728m loss in the fourth quarter, mainly due to an accounting charge related to its struggling Venezuela operations.