Halutz takes responsibilty for war failings
Israeli army radio reported that Halutz had accepted responsibility for Israel's a failure to achieve its war against Hezbollah.
"For me the concept of responsibility is everything," Halutz wrote in his resignation letter, army radio reported.
Halutz previously admitted he had committed several mistakes during the war, most notably taking a belated decision to call up thousands of reserve troops ahead of a major ground offensive, and the army's failure to curb thousands of rockets fired from Lebanon against northern Israel.
Criticism of war's conduct
The government of has come under intense criticism over the war which fell short of its goals of stopping Hezbollah from firing rockets into Israel and securing the release of two captured soldiers.
More than 160 Israelis died in the war, together with more than 1,100 Lebanese.
Other criticism focused on the lack of Israeli intelligence on Hezbollah.
Israeli troops entering Lebanon were surprised to find that the Shia militia had constructed  hundreds of deep and well-prepared bunkers capable of withstanding airstrikes.
Israeli media reports have also suggested that Israel's military was underprepared for fighting Hezbollah while some units also suffered from a lack of food and water once they had crossed the Lebanese border.