* No coalition deal in sight
* Deadline for an agreement expires on Wednesday
* Election would be Israel's third in less than a year
* Inconclusive ballots were held in April and September
* Indicted in corruption case, Netanyahu remains PM
By Jeffrey Heller
JERUSALEM, Dec 9 (Reuters) - Israel's two biggest parties agreed on Monday on a March 2 election date, barring a last-minute power-sharing deal, with Prime Minister Benjamin Netanyahu fighting for political survival under criminal indictment.
A 21-day period in which parliament can nominate a legislator with majority support to try to put together a ruling coalition expires at 2200 GMT on Wednesday, triggering the legislature's dissolution and an election within 90 days.
It would be Israel's third national ballot in less than a year. Recent opinion polls have predicted no dramatic shifts among voters since inconclusive elections in April and September.
Neither Netanyahu's right-wing Likud party nor the centrist Blue and White party led by his main rival, former military chief Benny Gantz, won enough seats in parliament for a governing majority in the previous two contests.
Both men were delegated the task of forming a coalition, but failed, throwing the ball into parliament's court. Their parties have been deadlocked in talks on a "unity" administration in which Netanyahu and Gantz would take turns as prime minister.
The two parties, which disagree over which man would serve first and for how long, announced they had agreed on the March 2 election date. The date needs parliament's approval but the two parties dominate the assembly so it is sure to pass.
The political disarray and a long-running corruption investigation have threatened to curtail Netanyahu's decade-long hold on power. Last month, Netanyahu, 70, was charged with bribery, breach of trust and fraud.
Denying any wrongdoing, he has accused Israel's legal authorities of attempting a "coup" aimed at ousting a popular right-wing leader. Critics alleged that Netanyahu was trying to undermine the rule of law and set an election campaign theme portraying himself as the victim of "deep state" conspiracy.
As prime minister, Netanyahu is under no legal obligation to resign following the indictment. A caretaker premier remains in the post until a new government is formed - a process that could stretch months past a March ballot if coalition-building is taken into account.
Before the national poll, Netanyahu would face an internal Likud leadership election. No date has been announced and only one challenger has emerged, former cabinet minister Gideon Saar, with no signs of any broad party revolt to oust Netanyahu.
In a speech on Sunday, Netanyahu said he hoped to avoid another election, "but if one is forced upon us, we will win big." (Editing by Timothy Heritage)