Italian bond yields have spiked this week, a sign that markets are questioning the country's ability to repay its bonds. Unlike Greece, Portugal or Ireland -- all of which received financial lifelines -- Italy has too much debt to be rescued by its European neighbors.
Italian Premier Silvio Berlusconi's main coalition ally urged him to step aside Tuesday ahead of a vote that could force his resignation. Many investors believe a new government would enact additional austerity measures that could help Italy cut its debt and remain in the euro zone.
Europe's debt crisis has dictated much of the trading in financial markets since the beginning of October. Investors fear that a disorderly default by Greece or another nation that shares the euro as a currency will lead to a widespread financial crisis similar to the one in 2008 after the fall of Lehman Brothers.
Dow futures were up 79 points, or 0.7 percent, to 12,086 an hour before the market opened. S&P 500 futures rose 7, or 0.6 percent, to 1,264. Nasdaq 100 futures gained 19, or 0.8 percent, to 2,388.
European shares were broadly higher. Italy's benchmark index rose 2.5 percent. Benchmark indexes in Germany and France were up 2.3 percent.
Tuesday is a quiet day for economic news in the U.S. The Labor Department will report on job openings for September.
Priceline.com Inc. rose 2.5 percent in premarket trading after it said that its third-quarter earnings more than doubled from a year earlier. Most of the gains were attributed to a jump in hotel bookings.
Activision Blizzard Inc. gained 3.5 percent in premarket trading ahead of the company's earnings report. Investors expect the company's latest "Call of Duty" video game to sell about 10 percent more units than last year's version.
Auction house Sotheby's fell 2 percent in premarket trading after the company posted a wider-than-expected loss in the third quarter.