Romano Prodi's center-left coalition has won leadership posts in both houses of Italy's parliament.
Franco Marini was elected president of the Senate by a margin of nine votes in a fourth round of tense balloting Saturday.
Hours earlier, communist leader Fausto Bertinotti was elected president of parliament's lower house by winning a simple majority in the Chamber of Deputies.
The victories were the first test of Prodi's coalition, which claimed victory over Prime Minister Silvio Berlusconi in Italy's national elections earlier this month.
Mr. Prodi is attempting to form a new government from a broad alliance that includes communists and Roman Catholic moderates.
Some information for this report was provided by AFP, AP and Reuters.