ROME (AFP) -- Italy awaited final confirmation of center-left leader Romano Prodi's narrow election victory as Prime Minister Silvio Berlusconi's challenge of the outcome appeared to run out of steam.

Prodi brushed aside a last-ditch appeal Saturday by Berlusconi for a short-term power-sharing government, made in a letter to the daily Corriere della Sera.

The 66-year-old center-left leader dismissed the overture, instead demanding an apology from the conservative prime minister.

"After what he said about vote-rigging, he should ask for forgiveness," Prodi told reporters outside his home in Bologna. He had said late Friday: "It's time that we close this strange comedy and move forward." Berlusconi had proposed that the rival coalitions forge a short-term agreement "to meet the country's immediate institutional, economic and international timetable."

His battle to stay in power suffered a severe blow Friday when it emerged that there were too few disputed votes to reverse the outcome of the election -- won with a desperately slim majority by Prodi's center-left coalition.

Italy's supreme court, the Corte di Cassazione, still has to rubber stamp the provisional result of the polls conducted last Sunday and Monday, but can only do so once the ongoing review of disputed votes is complete.

Further developments will likely be stalled by the Easter holidays Sunday and Monday, observers said.

The 69-year-old Berlusconi has remained defiant but patience with his stance has been growing thin, even within his own coalition. Berlusconi said in the letter to Corriere that Italy faced "a stalemate, with a situation in which, at least based on the popular vote, there will be neither winners nor losers." Berlusconi, speaking to reporters late Friday, said: "Common sense shows that we need a moment of reflection in the interests of all. If there isn't this moment of reflection, we will be in parliament to be an opposition which will certainly be very rigorous."

It was the closest Berlusconi has come to an admission of defeat, and his vague offer of a power-sharing deal to Prodi appeared to be a last gasp.

It came after the prime minister's hopes of a victory at the ballot box appeared dashed after the interior ministry admitted miscounting the number of disputed ballots cast in the election, putting the number at 5,266 votes instead of an earlier provisional figure of 82,850.