* Crude falls after 4-day rally
* ADP employment data on tap
* Futures off: Dow 32 pts, S&P 7 pts, Nasdaq 15.25 pts
By Chuck Mikolajczak
NEW YORK, Feb 4 (Reuters) - U.S. stock index futures dipped on Wednesday, after a two-day rally for the S&P 500 ahead of data on the labor market and the services sector.
* The benchmark S&P index jumped more than 1 percent for a second straight day on Tuesday, powered by energy shares as oil prices continued their recent run higher, with upbeat January auto sales also boosting the climb.
* Investors will eye the January private-sector employment report from payrolls processor ADP at 8:15 a.m. (1315 GMT) for signs of continuing improvement in the labor market. Expectations call for 225,000 jobs, down from the 241,000 jobs added in December.
* The S&P 500 has gained 2.8 percent over two sessions as the bounceback in oil prices and hopes of a Greek debt deal eased some concerns about the global economy, although the index has been locked in a trading range of 1,972 to 2,093 since mid-December and is nearly flat since Dec. 31. Equities have seen more volatility in 2015, with the daily trading range in the index often double its average over the past year.
* Later in the session at 9:45 a.m. (1445 GMT), financial data firm Markit will release its final January reading on the services sector. At 10 a.m. (1500 GMT), the Institute for Supply Management will release its reading on the services sector.
* Oil prices declined after a four-day rally of nearly 20 percent as a new build in U.S. crude stock levels put a global glut back in focus. U.S. crude was down 3 percent to $51.44 and Brent was off 2.1 percent to $56.68. Contract driller Transocean fell 1.4 percent to $18.14 in premarket trade.
* Gilead Sciences shares dropped 5.9 percent to $100.90 in premarket after the drugmaker posted quarterly results and said it is offering steeper-than-expected discounts on its hepatitis C drugs to health insurers and other group payers who had complained about the price.
* Office Depot shares were up 6 percent to $9.84 per share before the opening bell. Staples said it would buy its rival for $6.3 billion in cash and stock.
* European stocks were flat but better-than-expected results from LVMH sparked a rally in the shares of luxury goods makers. In Asia the Nikkei closed 2 percent higher as banks outperformed on strong earnings from Mitsubishi UFJ Financial Group.
Futures snapshot at 7:25 a.m. EST (1225 GMT):
* S&P 500 e-minis were down 7 points, or 0.34 percent, with 128,343 contracts changing hands.
* Nasdaq 100 e-minis were down 15.25 points, or 0.36 percent, in volume of 20,105 contracts.
* Dow e-minis were down 32 points, or 0.18 percent, with 22,780 contracts changing hands. (Reporting by Chuck Mikolajczak; Editing by Chizu Nomiyama)