She said Lieutenant-General Dan Halutz, 58, told Prime Minister Ehud Olmert and Defence Minister Amir Peretz that he was quitting "as the investigations have run their course."

"With the echoes of battle having faded, I have decided to act on my responsibility," the spokeswoman quoted Halutz as saying in his resignation letter.

The July-August assault on Lebanese Hezbollah guerrillas drove them from Israel's northern border but failed to retrieve two captive soldiers, prompting many Israelis to call for a purge of the top brass in hope of restoring a military edge.

A retired Israeli general, Dan Shomron, recently handed in the findings of a probe he conducted into the war's execution.

Shomron's report, released in part last month, criticised Israeli military commanders for poor organisation during the war but stopped short of calling for Halutz's resignation.

At the time, Halutz said he was staying on, though two generals who had served on the northern front stepped down.

A government-appointed commission of inquiry is separately looking into the conduct of Olmert and Peretz, its work doing little to mollify Israelis who had demanded a more independent investigation.

The so-called Winograd Committee's interim report is expected to be out within weeks, and Halutz's resignation could stoke public pressure on Olmert and Peretz to follow suit.

Halutz, a former air force chief, came under criticism for relying heavily on aerial barrages in the first part of the war, which caused extensive damage to Lebanon's infrastructure while Hezbollah launched around 4,000 rockets into Israel.

Some 1,200 mostly civilian Lebanese and 157 Israelis, most of them soldiers, died in the 34-day conflict, which erupted after Hezbollah seized the two troops in a deadly border raid.