Stock futures tumbled more than 2 percent on Monday in electronic trading, hit hard after European markets slumped on renewed fears the euro zone's sovereign debt crisis is worsening.
European stocks fell 4 percent on Monday, with financial shares falling to their lowest in more than 2 years. Wall Street was closed on Monday for a holiday.
Italy's FTSE MIB <.FTMIB> fell 4.8 percent, on renewed euro zone debt worries, and bond yields on Italian and Spanish government bonds hit their highest levels in nearly a month as pressure mounts on Italy -- the euro zone's third-largest economy -- to get rising deficits under control.
S&P 500 futures lost 26.10 points, or 2.2 percent, to 1143.30, suggesting a sharp drop at the open of U.S. trading Tuesday morning. Nasdaq 100 futures lost 39.5 points, or 1.8 percent, to 2124.50.
(Reporting by David Gaffen; Editing by Carol Bishopric)