Greek Premier George Papandreou said he will put Greece's bailout deal through a referendum, throwing the long-awaited deal into disarray and sending European stocks down 3.2 percent. The region's bank shares fell 6 percent.
Most Asian stock markets fell after data showed factory activity in the region's export powerhouses slowed to near three-year lows in October on lower European demand, reinforcing fears the euro zone's debt troubles were sapping global growth.
U.S. bank shares were expected to follow European lenders lower. The Financial Select Sector SPDR fell 2.3 percent in light premarket trading.
S&P 500 futures dropped 22.1 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 lost 144 points and Nasdaq 100 futures slid 36 points.
S&P 500 futures fell below their 14-day moving average for the first time since October 6 early Tuesday, pointing to a possible shift in short-term momentum. Stocks closed on Monday their best month in 20 years.
China's factory activity last month was its slowest since February 2009, the government said, an unexpected decline that reflected a drop in new export orders. The overall index dipped to 50.4 from September's 51.2, edging closer to the 50 line that separates growth from contraction.
In a move that could further weigh on commodity prices and risky assets, Japan vowed to step into foreign exchange markets again to curb excessive speculation a day after it reportedly sold a record 7.7 trillion yen ($98.7 billion) to tame its high-flying currency.
In the United States, the ISM Manufacturing Index is expected to edge up to 52.0 in October from 51.6, based on a Reuters poll. The data is due at 10 a.m. EDT (1400 GMT).
The Federal Open Market Committee kicks off its two-day policy-setting meeting later Tuesday. The FOMC is likely to take a break from policy changes after two consecutive easing actions.
The chances of a U.S. recession have fallen to 25 percent from 35 percent, said Credit Suisse, which also raised its year-end target for the S&P 500 index by 7.6 percent to 1,270.
Drugmaker Pfizer Inc report better-than-expected quarterly results early Tuesdays.
(Reporting by Rodrigo Campos)