Political turmoil in Italy is sparking fears among global investors.

Voters have made it clear they oppose budget cutbacks designed to battle Italy's massive debt, throwing strong support behind former Premier Silvio Berlusconi.

The final outcome of the election is still uncertain but the news is worrying investors, reviving fears of the eurozone debt crisis.

If Italian parties fail to form a governing coalition, new elections would be required, causing more uncertainty and a leadership vacuum.

The worry across Europe, and in financial markets everywhere, is that Italy's appetite for reform may wane and its debt situation may deteriorate.

Italy is hugely important for the future of the euro, and its apparent stability over the past six months has been one of the reasons that concerns over the currency have eased.

Of the 17 European Union countries that use the euro, Italy has the second highest debt burden as a proportion of its gross domestic product, at 127 percent.

U.S. stocks dropped Monday in their worst decline in more than three months.