U.S. stock index futures fell on Monday as lingering concerns over fraud charges against Goldman Sachs weighed on investor sentiment.

Bank stocks will be in focus following a steep decline Friday after U.S. regulators charged Goldman Sachs Group Inc with fraud related to the sale of investments tied to subprime mortgages.

Goldman shares were little changed in premarket trading after falling nearly 13 percent Friday. The Select Sector SPDR Financial ETF dropped almost 1 percent early Monday.

It's all about the aftershocks of the Goldman news, which will continue to weigh, said Peter Cardillo, chief market economist at Avalon Partners in New York.

Questions surrounding Goldman were increasing chances of tougher financial reforms as politicians in the United States and Europe called for closer scrutiny and tighter rules for banks, which could hurt profits.

S&P 500 futures fell 6.5 points and were below 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 lost 55 points, and Nasdaq 100 futures dropped 9.75 points.

Germany and the U.K. will seek details from the SEC about Goldman's activities ahead of possible legal steps against the banking powerhouse.

U.S. Treasury Secretary Timothy Geithner said Sunday he was confident lawmakers will bridge partisan differences on overhauling financial regulations and pass a bill that protects taxpayers from financing future bailouts.

Investors will also eye quarterly earnings from Citigroup Inc , which is due before Wall Street opens.

Hasbro Inc shares jumped 5 percent to $41.80 in low premarket volume after the toymaker reported a larger-than-expected quarterly profit.

Earnings can help cushion a severe decline, but the overall trend is the next few days is lower, Cardillo said.

Among other companies set to report are International Business Machines Corp , Eli Lilly and Co , M&T Bank Corp and Zions Bancorp .

Airlines will be in the spotlight as widespread disruptions swept across European and U.S. airports due to a volcanic ash cloud that forced the cancellation of tens of thousands of flights.

Investor risk aversion also hit the euro in favor of the low-yielding yen, while the U.S. dollar index <.DXY>, a gauge of the greenback against a basket of currencies, rose 0.5 percent.

U.S. data set for release Monday include the Conference Board's Leading Indicators for March, due at 10 a.m. EDT.

(Editing by Jeffrey Benkoe)