Stock index futures were little changed on Thursday after investors pushed up stocks for three straight sessions, betting leaders come up with a solution to euro zone debt crisis at an upcoming summit.

The European Central Bank cut interest rates Thursday to counter the twin threats of recession and deflation. Market participants were also looking for any hints it will intensify bond buying for the region's struggling peripheral economies.

Despite choppy trade, Wall Street has risen for three straight days on optimism European leaders forge a plan to fight the crisis at Friday's summit.

If the meeting disappoints, stocks may give up gains of about 9 percent, reached since November 25. European stocks edged up 0.2 percent in light volume early Thursday.

Late Wednesday, Standard & Poor's warned it could cut the credit ratings of the European Union and large area banks if a mass downgrade of euro zone countries materializes. The rating agency has said it may downgrade nearly all 17 euro zone countries if no solution emerges to solve the crisis.

The fear that countries could be downgraded has already been largely built in. But still, it's a positive that even with all the uncertainty we haven't had a selloff, said Christian Wager, chief executive at Longview Capital Management in Wilmington, Delaware.

S&P 500 futures fell 2.4 points and were 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 were off 3 points, and Nasdaq 100 futures rose 6.75 points.

Boeing Co's biggest labor union ratified a four-year contract extension late Wednesday, ensuring a new version its 737 narrowbody plane will be built in Washington state and likely ending a dispute with the National Labor Relations Board.

Weekly jobless claims are scheduled for release at 8:30 a.m. EST and are seen falling to 395,000 from 402,000 in the previous week.

Costco Wholesale Corp reported first-quarter earnings and revenue that rose from the prior year.

McGraw-Hill Cos Inc launched a $500 million share repurchase program and said it will cut about 550 jobs from its textbook unit as it splits into two companies.

Hopes for a euro zone solution inspired enough buying to push U.S. stocks to a third day of gains on Wednesday in light trading.

(Reporting By Ryan Vlastelica; editing by Jeffrey Benkoe)