In the Senate, the Interior Ministry assigned Prodi's coalition four of six seats chosen by Italians voting abroad. The tally gave Prodi a total of 158 seats to 156 for Berlusconi, leaving Prodi the minimum necessary to claim majority the house. The ministry assigned the seats on its Web site, even though full returns from overseas polling stations weren't completely tabulated.

For hours after polls closed Monday afternoon, projections and returns swung dramatically back and forth between the two coalitions, and without the vote from Italians living abroad, the election's outcome remained unclear. Voter turnout was about 84 percent.

"These results mean the country is divided in two. There needs to be a provisional government for a few months, then new elections," Marco Piva, a 49-year-old banker from Padua, said on his way to work. "This is the worst result that we could have had."