US STOCKS-Index futures edge higher after M&A flurry

* Wal-Mart offers $4 bln for South Africa's Massmart

* AirTran soars after Southwest bid

* Unilever to buy Alberto Culver for $3.7 bln

* Futures up: Dow 6 pts, S&P 500 0.5 pt, Nasdaq 1.75 pts

* For up-to-the-minute market news see [STXNEWS/US] (Updates market activity)

By Edward Krudy

NEW YORK, Sept 27 (Reuters) - U.S. stock index futures edged higher on Monday following four weeks of gains for Wall Street as investors eyed a flurry of merger-and-acquisition deals, a sign that companies are seeing value in the market.

Wal-Mart Stores Inc , the world's largest retailer, offered more than $4 billion for Massmart, South Africa's third largest listed retailer by value, as it seeks to expand in Africa. For details, see [ID:nLDE68Q05T]

Consumer goods giant Unilever Plc agreed to buy Alberto Culver Co , the U.S. hair care group for $3.7 billion in cash. Alberto Culver shares rose 18 percent to $37.10 in premarket trading. [ID:nLDE68Q07C]

U.S. stocks have moved higher in the last four weeks, with the benchmark S&P 500 index up over 9 percent since the start of September as investors welcomed signs the economy was on firmer footing.

"With the impressive surge on Friday, investors are pausing while gauging the commitment to additional optimism," said Andre Bakhos, director of market analytics at Lek Securities in New York. "The M&A deals should give investors an added boost of confidence."

S&P 500 futures rose 0.5 point and were above 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 gained 6 points, and Nasdaq 100 futures added 1.75 points.

Shares of AirTran holdings Inc rose 60.4 percent to $7.30 after Southwest Airlines Co said it would acquire the regional carrier in a deal valued at $7.69 per share. [ID:nSGE68Q0GW]

French drugmaker Sanofi-Aventis is seeking to line up more funding to raise its $18.5 billion bid for Genzyme Corp , The Wall Street Journal reported. [ID:nLDE68Q0BV]

Preorders in China for Apple Inc's iPhone 4 have exceeded 200,000 units since the smartphone went on sale Saturday, China Unicom said. [ID:nTOE68Q03F]

On the earnings front, Jabil Circuit Inc and Paychex Inc are due to report results later Monday. On the macroeconomic side, investors are awaiting the Chicago Fed National Activity Index for August and the Chicago Fed Midwest Manufacturing Index for August.

European stocks edged up on Monday, extending Friday's sharp gains, with food and beverages shares among the top gainers after the Unilever-Alberto Culver deal. The Nikkei 225 index closed up 1.4 percent.

U.S. stocks notched their fourth week of gains on Friday as investors used a rise in business spending to revive the September rally after three days of losses.

The next resistance on the S&P 500 it at around 1,173, the highest level since May 6, when it lost nearly 100 points intraday during the "flash crash." The index closed up 2.1 percent at 1148.67 on Friday. (Reporting by Edward Krudy; editing by Jeffrey Benkoe)