S&P index futures cut earlier losses to turn flat on Wednesday as acquisition activity helped to offset weaker-than-expected ADP employment data.

S&P 500 futures rose 0.6 percent and were about even with 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 1 point, and Nasdaq 100 futures rose 0.25 points.

U.S. private employers added 179,000 jobs in April, according to a report by ADP Employer Services, less than economists' expectations.

Varian Semiconductor Equipment Associates Inc surged 52 percent in premarket trading after Applied Materials agreed to buy the company for $4.9 billion in cash.

(Reporting by Ryan Vlastelica)