Silvio Berlusconi will support the leader of Italy's euroskeptic partner the League in attempts to form a government, the former prime minister said in a newspaper interview on Wednesday.
The four parties in the center-right coalition agreed during the campaign that the leader of the party that won the most votes would head a government.
In a personal defeat for Berlusconi, the far-right League surpassed his Forza Italia (FI) party in Sunday's elections, winning about 17 percent of the vote to 14 percent for FI.
"In full respect of our agreements, we will now loyally support attempts by (Matteo) Salvini to form a government," Berlusconi told Corriere della Sera.
"I am here to support him, to guarantee the solidity of the coalition and keep our commitments with the voters," he said.
The vote produced a hung parliament and talks to form a government will take weeks and possibly months. The League and the anti-establishment 5-Star Movement both say the president should name their own leaders as prime minister.