The Senate approved a bill that effectively grants Prime Minister Silvio Berlusconi immunity from prosecution during his term, the ANSA news agency reported. The law grants immunity to Italy’s four most powerful elected officials, the prime minister, the president and the speakers of the two chambers of Parliament, while they are in office. The lower chamber had already approved it. The most immediate beneficiary is Mr. Berlusconi, who had been awaiting trial, accused of paying his British lawyer, David Mills, $600,000 to give favorable testimony in two trials.