Stock index futures were flat on Monday as investors awaited data on personal spending for a signal the economy can avoid a double-dip recession and after a flurry of mergers-and-acquisition activity.

France's Sanofi-Aventis disclosed a cash offer of $18.5 billion, or $69 per share, for Genzyme Corp after failing to start merger talks with the U.S. biotechnology company. Genzyme's board rejected the proposal.

Shares of Genzyme rose 4.1 percent to $70.40 in premarket trading, and U.S.-listed shares of Sanofi were up nearly 1 percent to $29.17.

German chipmaker Infineon Technologies AG agreed to sell its wireless unit to Intel Corp for $1.4 billion, enabling the U.S. chipmaker to boost its presence in the smartphone market.

Intel shed 0.1 percent to $18.35 in premarket.

Investors are being a tad apprehensive as the market has had a very fickle personality as of late, said Andre Bakhos, director of market analytics at Lek Securities in New York. In addition to the M&A, the market is looking for an extra reason to come off the sidelines.

At 8:30 a.m. EDT July personal income and consumption data as well as core PCE data is due. Wall Street expected consumption to rise 0.3 percent versus no change in June.

Any data showing an increase in economic activity would help stave off any recessionary themes playing out in the market, added Bakhos.

Dell Inc said it is assessing a bid for data storage company 3PAR Inc
after 3PAR's board said late Friday that Hewlett-Packard Co's $2 billion offer was a superior proposal.

Cogent Inc shares were halted in premarket after 3M Co agreed to acquire the maker of fingerprint identification systems for $943 million, or $10.50 per share.

S&P 500 futures slipped 0.5 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 lost 11 points, and Nasdaq 100 futures fell 1 point.

European shares were little changed in thin trading Monday, with persistent concerns about the sustainability of the global economic recovery weighing on sentiment.

In Asia, Japanese shares ended 1.8 percent higher but gave up strong early gains after the Bank of Japan made only minor tweaks in policy, disappointing markets looking for more aggressive action against deflation.

Stocks rebounded to post their best gains in nearly four weeks on Friday, overcoming initial skittishness brought on by a revenue warning from Intel and after Fed Chairman Ben Bernanke said the economic recovery had weakened more than expected.

(Reporting by Chuck Mikolajczak; editing by Jeffrey Benkoe)