FACTBOX: Possible successors to Olmert

(Reuters) - Defense Minister Ehud Barak called on Wednesday on Ehud Olmert to step aside as Israel's prime minister. These are Olmert's potential successors:

TZIPI LIVNI - Foreign minister and chief negotiator with the Palestinians, Livni is seen as the likeliest successor from within Olmert's centrist Kadima party. The most powerful woman in Israel since Prime Minister Golda Meir in the 1970s, Livni, 49, called on Olmert to quit last year after a scathing report on Israel's 2006 war in Lebanon. He didn't. Nor did she. Daughter of a prominent right-wing Zionist, she is a former intelligence agent. Like Olmert and former prime minister Ariel Sharon, she left the right-wing Likud party in 2005 to found Kadima.

EHUD BARAK - Defense minister who leads the Labour party, the main coalition ally. Barak is not a member of parliament so could not become prime minister without first winning a seat. A much-decorated commando, top general and prime minister (1999-2001), Barak, 66, has stood by Olmert since he was quizzed by police on Friday. But when he campaigned last year for the Labour leadership, he said Olmert should quit if an inquiry found fault with him over the Lebanon war. Earlier this year, it did. But Barak said he would call for Olmert to go "at a more convenient time".

BENJAMIN NETANYAHU - Prime minister from 1996-99 and leader of the opposition Likud party since Sharon, Olmert and others bolted to Kadima. Educated in the United States, he became a decorated commando. As finance minister under Sharon from 2003, Netanyahu, 58, pursued economic reforms that angered the left but are credited by many for economic growth. Tops many polls as likely winner if parliamentary election, not due until 2010, is called early.

HAIM RAMON - A close Olmert confidant, Vice Premier Ramon quit the Labour party to join Kadima. He was forced to briefly resign his cabinet post following his conviction for indecent assault against a woman soldier but was allowed to return as a minister by an appeal court. He is one of the government's most active supporters of peace talks with the Palestinians.

(Editing by Richard Balmforth)