Italy's Prime Minister Silvio Berlusconi pulls at his collar during a Senate session in Rome April 20, 2005. (Reuters)

ROME, April 20 (Xinhuanet) -- Italian Prime Minister Silvio Berlusconi handed in his resignation Wednesday to President Carlo Azeglio Ciampi and pledged to form a new government to tackle the worst political crisis in his four-year tenure.

    The Presidential Palace Quirinale said in a statement that Berlusconi has tendered the resignation of his Cabinet, but did not specify whether the president has accepted it or not.

    The president asked Berlusconi and his government members to hold their responsibilities in their posts till Thursday, when more discussions are scheduled to be held, said the statement.

    The centre-right leader Berlusconi, the country 's longest-serving premier in Post-World War II period, had long been under pressure to resign since his party suffered a stunning defeat in regional elections earlier this month.

    However, Berlusconi announced his resignation earlier in the day to the Senate, stressing that he aimed to remain in power with the same coalition for a full five-year term but would overhaul his program in the wake of a heavy local election defeat.

    "I have understood the signal... but am confident that this difficult moment can be overcome," said Berlusconi, who swept to power in 2001 on a pledge of lower taxes.

    "I am certain we will complete the mandate that voters have given us," said the billionaire media magnate.

    Berlusconi's government was plunged into a political crisis last week when his disgruntled coalition ally Catholic UDC withdrew from the government after failing to demand radical policy changes for the economy, the south and lower income families.

    Once a government resigns, it is up to the president to designate a candidate to try to form a new one or else dissolve parliament and call early elections. Ciampi is likely to give Berlusconi a new mandate. Enditem