NEW YORK (AP) — Stock futures fell sharply Wednesday amid growing concerns that Italy's debt levels are unsustainable.

Italian bond yields spiked above 7 percent, a sign that investors are losing faith in the country's ability to repay its debt. Analysts say Italy will not be able to refinance its debt at current rates, which will force it to either enact deep austerity measures or to receive financial assistance to prevent a default.

Greece, Portugal and Ireland each required bailouts when their bond yields rose above 7 percent. But unlike those countries, Italy's $2.6 trillion in debt is too large for other European nations to bail out.

Europe's debt crisis continued in Greece as well. The country's two main political parties are still engaged in power-sharing negotiations and have yet to name a prime minister to lead the interim government. The new government must pass an austerity package to receive the next loan installment in its bailout. Without the funds, Greece could default before Christmas.

Markets fear that a disorderly default by either Greece or Italy would lead to huge losses for banks. That could cause lending to freeze up, potentially causing a credit crisis similar to the one in 2008 after the U.S. investment firm Lehman Brothers fell.

Dow Jones industrial average futures dropped 222 points, or 1.8 percent, to 11,902 an hour before the market opening. S&P 500 futures lost 30, or 2.4 percent, to 1,242. Nasdaq 100 futures shed 44, or 1.8 percent, to 2,350.

In the U.S., the government will issue the September wholesale trade report, which may give clues to the pace of factory production.

In corporate news, General Motors Co. lost 7 percent in premarket trading after its third-quarter profit fell 15 percent from the same period last year. The company said it would not be able to meet its target of breaking even in Europe this year. Fast-food company The Wendy's Co. dropped 4.5 percent in premarket trading after the company said higher beef prices contributed to a larger third-quarter loss. Dean Foods fell 2.5 percent after the company took a write-down in its fresh dairy business.