As widely expected, D'Alema told a late night debate in the Chamber of Deputies that he was offering the head of state his resignation as leader of Italy's 56th government since World War II. He arrived at the presidential palace on the Quirinal Hill shortly after.
President Carlo Azeglio Ciampi can reject the bid, or, in what was seen as the probable scenario, ask D'Alema to try to forge another center-left coalition, which would then face a vote of confidence in Parliament.
D'Alema's center-left coalition has been torn by fighting among partners for weeks. Earlier this month, the Socialists, one of the tiniest parties in the 14-month-old government, demanded he step down.
The coalition has been weakened almost from the start by disagreements among partners over issues ranging from Italy's support of NATO's bombing campaign last spring against the former Yugoslavia, to proposals to speed up pension reforms.
Earlier, contending the country didn't need "traumatic" early elections, D'Alema pitched for a renewed, stronger government.
D'Alema made clear he would like to see another center-left coalition put into place rapidly. State radio reported earlier in the day he hopes to achieve that by Christmas.
Italian political reporters have calculated that D'Alema can count on support from 318 of the 630 members in the Chamber of Deputies, which would allow him to squeak by in a confidence vote. A confidence vote would be required if he winds up forming a new government.
"The country doesn't need lacerations and much less a traumatic dissolving of the legislature," D'Alema told the deputies. Rather, he said, it needs "a government that operates in the fullness of its functions and that is put into the condition to achieve necessary and possible reforms."
Despite a love of Woody Allen films and a passion for sailing, D'Alema, a former editor of party paper L'Unita, comes across as an intellectual who does not suffer fools gladly.
``When he applies himself to something he can be really unpleasant,'' his wife Linda Giuva once told an interviewer. ``Some people like him a lot and some hate him from the bottom of their heart. But everyone knows he's very capable.''
The opposition was scathing in its reaction of D'Alema's bid for a renewed mandate.
"If he wanted to put on a new farce, D'Alema couldn't have done better," said Enrico Loggia, Senate whip for Berlusconi's Forza Italia party. "Unfortunately there are problems, and this government and its majority aren't able to face them. And when it's that way, it's better to go back to the voters."