JERUSALEM (Reuters) - Israeli Prime Minister Benjamin Netanyahu's indictment, which prosecutors referred on Monday to parliament on three corruption cases, included more than 300 witnesses, including wealthy friends and former aides.

Sending the indictment formally to the Knesset after the bribery, dishonesty and fraud charges were announced on Nov. 21 means that Attorney General Avichai Mandelblit has begun the 30-day period in which Netanyahu can seek parliamentary immunity from trial.

Such parliamentary protection seems unlikely as turmoil is shaking up political life in Israel after inconclusive elections in April and September and Netanyahu and his main rival, Benny Gantz, failed to secure a ruling majority in parliament.

Netanyahu, who has ruled Israel for a decade, denied any wrongdoing, saying he was the victim of a "coup" attempt by the judiciary trying to isolate a popular right-wing leader.

As head of government, he is not required by law to resign after being charged.

No date has been set for the start of the trial by three judges at the Jerusalem District Court.

The indictment referred to Parliament included the names of 333 witnesses. Legal experts said the length of the list meant the trial could last years.

The list includes American nightclub magnate Sheldon Adelson, his wife Mary, Hollywood producer Arnon Melchan, Australian billionaire James Packer, retired Israeli security chiefs and a number of former aides who will be king witnesses.

Netanyahu mocked the length of the list of witnesses. "When there is a true accusation, you don't need 333 witnesses," he wrote on Twitter. "When the accusation is not true, the witnesses will not benefit even if they are 333," he said.

In one case, Netanyahu is suspected of illegally ordering and accepting precious gifts, including champagne and a cigar from Milchan and Baker. Neither was charged.

Another case focuses on allegations that Netanyahu promised the owner of Israel's most popular newspaper to press for regulations to apply to the rival newspaper, owned by Adelson.

Netanyahu is also accused of giving organizational benefits worth about NIS 1.8 billion ($ 500 million) to Israel's Bezeq Telecom in exchange for positive coverage of the prime minister at a news site owned by the former head of the company.

Talks between Netanyahu's Likud party and Gantz's blue-white party on forming a "national unity" government have reached a dead end.

If no agreement is reached within 10 days, the end of a three-week period in which Knesset members name one of them to form a new government, Israel must hold new elections.