U.S. stock index futures pointed to a flat open and another session of volatility on Thursday as renewed concerns about the euro zone banking system pushed down European shares.

U.S. stocks offered some bright spots, with Cisco rising before the bell after its results topped estimates.

Both the S&P 500 and Dow industrials were down more than 4 percent in the previous session on worries about Europe, and underscoring the choppy trading, the Dow has swung in a range of more than 400 points for five straight days.

French banking shares were hammered by worries about their stability as European stocks dropped 0.5 percent on Thursday, extending the previous day's losses. Reuters reported one bank in Asia had cut credit lines to major French lenders.

That report is the only thing it could be causing the selloff, said Peter Kenny, managing director at Knight Capital in Jersey City, New Jersey. This is not going away any time soon. Where there is smoke there is fire, and the appetite for risk, even rumored risk, is zero.

The latest U.S. economic data offered some relief. Initial jobless claims edged lower in the latest week, falling by 5,000 to 395,000 versus the forecast of 400,000. Equities pared losses after the data.

S&P 500 futures added 0.1 point 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 rose 14 points and Nasdaq 100 futures added 5.5 points.

Dow component Cisco Systems Inc advanced 12 percent to $15.37 in premarket trading a day after reporting quarterly revenue and profits that topped scaled-back expectations.

News Corp rose 3.6 percent to $14.20 before the bell after it posted higher operating profit and revenues.

When we're eventually able to return our focus to fundamentals, the good news out of Cisco and News Corp will help, said Robert Pavlik chief market strategist at Banyan Partners LLC in New York.

Corporate earnings this season have generally been strong, with a majority of companies topping Wall Street expectations for both profits and revenues, but the results have been overshadowed by concerns about huge government debt loads on both sides of the Atlantic and the U.S. economic slowdown.

Kohl's Corp gained 2.4 percent to $45.36 premarket after the department store chain's quarterly earnings beat expectations and it raised its full-year profit view. Sara Lee Corp fourth-quarter earnings fell from the prior year.

Worries about French lenders triggered a selloff in European and U.S. banks on Wednesday and contributed to the sharp decline in broader equities.

(Editing by Jeffrey Benkoe)