Stocks declined on Wednesday after disappointing results from Pfizer and transport companies, while slower-than-expected expansion in the services sector also weighed on the market.

Pfizer Inc
fell 1.6 percent to $18.75 and led a broad decline in several healthcare sectors after the world's biggest drugmaker said quarterly earnings missed estimates and forecast profits below expectations.

Health insurers dropped, with Cigna Corp down 2.7 percent to $34.30, and UnitedHealth Group Inc off 2.6 percent at $33.15. The Morgan Stanley Healthcare Payor Index <.HMO> fell 1.8 percent.

Logistics companies weighed on the transport sector after Ryder System Inc and C.H. Robinson Worldwide Inc reported weaker-than-expected profits.

Ryder fell 8.7 percent to $34.08, and C.H. Robinson tumbled 6.2 percent to $53.90, while the Dow Jones transportation average <.DJT> lost 1.3 percent.

There are concerns about earnings in healthcare ... and some of the policies that (the Obama administration is) looking at, said Dennis Cajigas, senior market strategist at Lind-Waldock in Chicago.

A healthcare overhaul has stalled in the U.S. Congress afterDemocrats lost the Senate seat in Massachustts, injecting uncertainty about the extent and strength of any reform.

Until Wednesday's open, the S&P healthcare index <.GSPA> ranked as the best performing sector in the S&P 500 so far this year. The index was off 1.3 percent on Wednesday.

The Dow Jones industrial average <.DJI> fell 23.51 points, or 0.23 percent, to 10,273.34. The Standard & Poor's 500 Index <.SPX> dropped 4.95 points, or 0.45 percent, to 1,098.37. The Nasdaq Composite Index <.IXIC> lost 1.23 points, or 0.06 percent, to 2,188.83.

The Institute for Supply Management said its services index rose to 50.5 in January from 49.8 in December, below the 51.0 median forecast of economists surveyed by Reuters.

A report by ADP Employer Services showed the pace of U.S. job losses in the private sector slowed in January, as employers reported the smallest payroll decline in nearly two years.

The closely watched government jobs report due Friday is expected to show continued improvement in U.S. employment.

(Additional reporting by Ellis Mnyandu; editing by Jeffrey Benkoe)