Stock index futures fell on Thursday after a late selloff in the prior session as investors kept a close eye on rising yields of euro zone debt.

Spanish bond yields hit 6.98 percent, their highest level since 1997, at a 10-year auction. A French bond auction also saw high yields.

The 7 percent mark is viewed by investors as unsustainable, with both Greece and Portugal forced to seek bailouts at similar levels, as Spain was pulled deeper into the euro zone debt crisis ahead of a parliamentary election on Sunday.

U.S. stock losses accelerated in the latter part of trading Wednesday after rating agency Fitch said while the outlook on the U.S. banking industry is stable, it could worsen if the euro zone crisis is not resolved quickly.

Resurfacing fears of contagion are in the forefront as comments were made late yesterday by Fitch, said Andre Bakhos, director of market analytics at Lek Securities in New York.

What is known is that there are problems, what is not known is the extent of any potential problems. For the moment, the market is taking a risk averse tack and until there is greater clarity, the market is going to experience erratic and volatile behavior.

Financial shares fell in premarket trading over concerns to their exposure to the region. Citigroup Inc lost 1 percent to $26.58 and the Select Sector SPDR ETF dipped 0.9 percent.

European shares fell to a five-week low in choppy trade as the rising euro zone sovereign bond yields heightened worries that the currency bloc's crisis would spread further and that the region is headed for recession. <.EU>

S&P 500 futures fell 3.2 points and were below fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration of the contract. Dow Jones industrial average futures were off 16 points, and Nasdaq 100 futures lost 5.75 points.

Asian shares wobbled as doubts deepened about Europe's ability to stop the crisis from spinning out of control, with Germany and France split over the European Central Bank's bond buying role.

Investors have recently been forced to weigh the threat of a deepening crisis against U.S. economic data that has been better than expected.

Economic data expected Thursday includes weekly initial jobless claims at 8:30 a.m. EST. Economists surveyed by Thomson Reuters forecast a total of 395,000 new filings, compared with 390,000 in the prior week.

Also at 8:30 a.m., the Commerce Department reports on housing starts and permits for October, while the Philadelphia Federal Reserve Bank releases November business activity survey, 10 a.m. EST.

Sears Holdings Corp's quarterly loss almost doubled as weak demand at its Sears and Kmart stores hurt sales, it reported early Thursday.

Chip gear maker Applied Materials Inc gave a cautious revenue outlook after the close on Wednesday and warned it expects to be affected by a tough economy.

(Reporting by Chuck Mikolajczak; editing by Jeffrey Benkoe)