Embattled Italian Prime Minister Silvio Berlusconi absorbed another blow Monday after his coalition suffered dramatic defeats in mayoral races in Milan, Naples and other cities, raising the possibility of early national elections and casting the 74-year-old leader's future in doubt.

The most important race was in Milan, the country's second largest city, where, the Ministry of Interior's website reported, incumbent Letizia Moratti, endorsed and supported by Berlusconi's coalition, was defeated by attorney and former parliamentarian Giuliano Pisapia by more than 10 points -- 55.1 percent to 44.9 percent with 96 percent of the vote counted. Moratti conceded defeat in the race late Monday, local media reported.

Berlusconi, a native of Milan, said the race was especially important to him, and some critics said that the stinging defeat could prove to be a nail in the political coffin of Berlusconi, whose woes also include a series of criminal and civil court problems and eroding approval levels.

"Berlusconi was politically born in Milan and in Milan he has politically deceased," said industrialist Carlo de Benedetti, a powerful Berlusconi rival.

Berlusconi's center-right coalition faced defeat elsewhere. In Naples, Italy's third largest city, Luigi de Magistris beat Berlusconi's handpicked candidate Gianni Lettieri by a whopping 65.3 percent to 34.7 percent margin.

Opposition candidates also carried the day in Cagliari, the capital of the island region of Sardinia, as well as in northern cities Trieste and Mantova.

There was no vote in Rome, the country's capital and largest city. All of Monday's results were from run-off races after no candidate managed to secure a majority in earlier first-round voting.

In Italy, local races are often seen as proxies for national figures, and the mayoral races were no exception,

Political commentators said the weak results for Berlusconi's candidates could antagonize the already difficult relationship between the prime minister and Umberto Bossi, the leader of the Northern League, the second leading party in the ruling coalition.

Bossi has criticized Berlusconi's leadership and said his legal problems and weak support levels were weighing down the coalition.

Matteo Salvini, a member of parliament from the Northern League, said Monday that the results of the latest round of voting should be seen as a "vote against Berlusconi."

If the Northern League decides to pull its support from Berlusconi's coalition or even if they elect to support only part of the coalition's platform it could spell trouble for Berlusconi and might even lead to early elections.

The current government's mandate is set to expire in 2013, but if Berlusconi's allies are forced to face any no-confidence vote without the support of the Northern League's full support the results would likely force the government to resign.

Even if that does not happen, the results likely mean that the government no longer has the political capital it needs to push through economic reforms the country needs to spark growth amid the current economic crisis.

And without stronger economic growth, pollsters say, Berlusconi's approval levels are not expected to improve.

"Berlusconi is in a difficult position, with declining approval levels, legal problems, coalition problems, and the poor results from the latest votes," Maria Rossi, co-director of polling firm Opinioni, told Xinhua. "The trouble is, it is not clear where his fortunes will be able to rebound," she said.