* Third Israeli election in less than a year

* Polls predict another stalemate

* Netanyahu running for office while under criminal indictment

* Corruption trial due to start on March 17

* Israel's longest-serving leader denies any wrongdoing

By Jeffrey Heller

JERUSALEM, March 2 (Reuters) - Israeli Prime Minister Benjamin Netanyahu seeks re-election on Monday under the weight of an imminent corruption trial, with the country's third ballot in less than a year predicted to end in another deadlock.

The election follows two inconclusive votes in April and September that dimmed an aura of political invincibility enjoyed by Israel's longest-serving prime minister, who has denied any wrongdoing in the three graft cases against him.

Opinion polls show neither Netanyahu's right-wing Likud nor the centrist Blue and White party of his main challenger, former armed forces chief Benny Gantz, securing enough votes on their own, or with coalition allies, for a governing majority in parliament.

A fourth election could ensue within months if the deadlock is not broken. Further stalemate could push Israel, where a 2020 budget is still pending, further into economic limbo.

Turnout figures will be watched closely, particularly given the concern over the global coronavirus outbreak and accusations of malicious rumours about contamination in areas seen as strongholds for particular parties.

Voters under home-quarantine, such as those who have recently travelled back to Israel from coronavirus hotspots, can attend special polling stations if they wear a surgical masks and show no signs of the disease.

Israel's economy has so far weathered the political turmoil, with growth strong and the labour market tight. But the longer the stalemate continues, the heavier the toll, including the lack of new money for health, education, welfare or infrastructure projects until an annual budget is approved by parliament.

Netanyahu's battle to win an unprecedented fifth term has become more complicated since the previous election, having been indicted on charges of bribery, breach of trust and fraud over allegations he granted state favours worth hundreds of millions of dollars to Israeli media barons in return for gifts and favourable coverage.

Netanyahu is due to go on trial on March 17, when post-election coalition wheeling and dealing is likely to be in full swing.

'THE DEFENDANT'

Playing the character card against Netanyahu, Gantz has dubbed him "the defendant" and alleged that he sought to retain power to promote legislation that would bar authorities from putting a sitting prime minister on trial.