* ADP, ISM Services, new home sales data on tap
* J.C. Penney jumps after November sales
* OmniVision slumps after revenue forecast
* Futures up: Dow 10 pts, S&P 0.1 pt, Nasdaq 3.75 pts
NEW YORK, Dec 4 (Reuters) - U.S. stock index futures were little changed on Wednesday, ahead of a flurry of economic data, including a report on the labor market.
* The S&P 500 has fallen for three straight sessions, partly on concerns the U.S. Federal Reserve may begin to reduce its stimulus earlier than some had anticipated, putting the benchmark index on track to snap an eight-week winning streak.
* Many market participants expect the central bank to announce a cut to its $85 billion in monthly bond purchases in March, but recent economic data has given rise to the possibility that timeline may be accelerated.
* The Fed has said it would begin to slow the program when certain economic measures meet its targets, including an improvement in the labor market.
* Investors will eye the November employment report from Automatic Data Processing at 8:15 a.m. EST (1315 GMT) for clues on hiring ahead of Friday's key payrolls report. Economists in a Reuters survey expect 173,000 jobs were created in November compared with 130,000 new jobs in October.
* At 10:00 a.m. (1500 GMT), the Institute for Supply Management releases its November non-manufacturing index and the Commerce Department releases new home sales for September and October.
Economists in a Reuters survey forecast an ISM services reading of 55.0 versus 55.4 in October. New home sales for September are forecast to show a total of 425,000 annualized units and 428,000 for October.
* Later in the session at 2:00 p.m. (1900 GMT), the Federal Reserve will release its Beige Book of regional economic conditions.
* S&P 500 futures rose 0.1 point and were slightly below fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average futures rose 10 points and Nasdaq 100 futures added 3.75 points.
* J.C. Penney Co Inc climbed 5 percent to $10.62 in premarket trading after the retailer said comparable sales, including e-commerce and sales at stores open at least a year, rose 10.1 percent during November, in the latest sign its turnaround is continuing.
* OmniVision Technologies Inc slumped 12.5 percent to $14 in light premarket trade after the chipmaker forecast current-quarter revenue well below analysts' estimates.
* European shares traded flat, steadying after the previous session's steep losses, with Asia-focused bank Standard Chartered the leading decliner after it warned its profits were likely to fall.
* Most Asian shares slumped as the prospects of a reduction in the U.S. Federal Reserve's stimulus early next year prompted investors to cash in gains from recent rallies.
* The Dow and the S&P 500 fell for a third straight day on Tuesday, dropping from record levels as investors took profits amid signs of a weak holiday shopping season.