S&P 500 index futures edged higher on Thursday, reversing an earlier decline, as investors were cheered by a big technology-sector acquisition and Portugal moved to stem its sovereign debt problems.

German software company SAP AG plans to buy smaller U.S. rival Sybase Inc for $5.8 billion to acquire technology that delivers business software to smartphones. Sybase surged 15.3 percent to $64.75 before the opening bell, while U.S.-listed shares of SAP were down 0.6 percent at $44.62.

M&A activity is always a good sign. I think we're going to see a lot more M&A activity as well, said Arthur Hogan, chief market analyst at Jefferies & Co in Boston.

SAP had a pile of cash, and they're not alone. There's a lot of cash on the sidelines, and you're going to see that being put to work.

Portuguese leaders agreed to tough new austerity measures, joining a coordinated euro-zone push to prevent Greece's debt crisis from spreading.

S&P 500 futures added 2 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 fell 12 points, and Nasdaq 100 futures rose 1.25 points.

Investors were also awaiting initial jobless claims due at 8:30 am EDT. First-time claims for jobless benefits are expected to dip to 440,000 last week from 444,000 the week before, according to a Reuters poll of economists.

On the downside, Cisco Systems Inc slipped 1.5 percent to $26.35 after its quarterly results beat expectations late Wednesday, but its chief executive was cautious about the economy as the U.S. employment picture remained weak.

Financial stocks could come under pressure after reports that five U.S. banks and four European lenders are being investigated by U.S. authorities in a widening probe of past mortgage securities deals.

Stocks capped their best three-day run in 10 months on Wednesday, boosted by tech and industrial shares, as Spain unveiled an austerity plan that reassured investors that Europe was addressing its fiscal ills.

(Editing by Jeffrey Benkoe)