Stock index futures rose Wednesday, putting the benchmark S&P 500 index on track to extend the prior session's big gains as banks borrowed more than anticipated at the European Central Bank's record cash injection aimed at easing the debt crisis.

Banks borrowed 489 billion euros ($641.08 billion) at the ECB's first-ever offering of three-year funding, boosting optimism that a credit crunch can be averted.

But the optimism appeared to fade, reflecting the financial pressure the European banks are under, as European stocks gave back early gains. The FTSEurofirst 300 <.FTEU3> was up 0.2 percent and German government bonds turned positive on the day. <.

S&P 500 futures rose 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 gained 42 points, and Nasdaq 100 futures added 2.75 points.

U.S.-listed shares of Research in Motion Ltd jumped 11.8 percent to $14 in premarket trade after Reuters reported the BlackBerry maker has rebuffed takeover overtures.

Oracle Corp slumped 8.8 percent to $26.59 premarket after posting earnings late Tuesday that fell short of Wall Street's forecasts for the first time in a decade.

On the economic front, the National Association of Realtors will release existing home sales for November at 10 a.m. EST. Economists in a Reuters survey forecast a 5.05 million annualized unit total versus 4.97 million annualized units in October.

Contract electronics manufacturer Jabil Circuit Inc posted first-quarter revenue below estimates and sees lower revenue in the second quarter.

Paychex Inc
recorded quarterly profit that beat expectations and said it continues to see a slow economic recovery with respect to sales from new clients.

In Asia, stocks rose after upbeat U.S. and German data and strong demand for Spanish debt tempered risk-aversion.

(Reporting By Chuck Mikolajczak)