U.S. stock index futures pointed to a higher open on Wednesday as data showed private employers added jobs in a sign of economic improvement and acquisition activity lifted sentiment.

Private employers created 201,000 jobs in March, according to ADP Employer Services, a rise that was in line with expectations.

The report by the payrolls processor is closely watched for insight into the health of the labor market, although it has little correlation with the government's broader non-farm payrolls report due on Friday.

ADP shows that the labor recovery continues at a reasonable pace, said David Katz, chief investment officer at Matrix Asset Advisors in New York, adding that the improving labor market should be a buffer against weak areas of the economy.

In the latest M&A activity, Canadian drugmaker Valeant Pharmaceuticals International on Tuesday made an unsolicited bid to buy Cephalon Inc for $5.7 billion, sending the stock up 29 percent to $75.97 in premarket trading while U.S.-listed shares of Valeant rose 16 percent to $51.40.

The bid follows AT&T Inc's recent proposed purchase of T-Mobile USA and eBay Inc's bid for GSI Commerce , signs that stocks could be viewed as cheap.

We expect to see acceleration in merger activity, which we think is a reasonable way for companies to redeploy cash and accelerate long-term growth, Katz said.

Chemical company and Dow component DuPont

extended its $6 billion takeover bid for Denmark's Danisco by four weeks. DuPont shares rose 0.8 percent to $55 in light premarket trading.

S&P 500 futures rose 6.3 points and were above 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 added 50 points and Nasdaq 100 futures rose 17 points.

Gains may be limited by uncertainties over Japan's nuclear power situation and civil unrest in oil-producing regions. Trading volume has been weak, with Monday and Tuesday posting the lowest and second lowest days of the year, respectively, suggesting shaky investor confidence before the quarter ends.

The S&P is currently up 4.9 percent in the first quarter, based on Tuesday's close.

Family Dollar Stores Inc reported second-quarter earnings that rose from the prior year and were at the high end of the company's forecast, which it recently raised. The stock rose 1.8 percent to $53.35 in premarket trading.

Toyota Motor Corp <7203.T> and Honda Motor Corp <7267.T> took fresh steps to scale back production or reduce orders of some parts in North America after supplies were disrupted by Japan's earthquake.

U.S.-listed shares of Toyota rose 1.1 percent in premarket trading.

Overseas, Japanese stocks hit their highest level since a post-earthquake sell-off as the yen weakened, while European shares hit a three-week high on strength in mining shares.

Strength in energy lifted U.S. stocks on Tuesday as investors concentrated on adding to winning positions, but uncertainty kept trading volume light.

(Editing by Kenneth Barry)