General Eric K Shinseki, the United States Army chief, retired on Thursday, but not without kicking up a minor controversy.

In his parting remarks, Gen Shinseki failed to mention Defence Secretary Donald Rumsfeld and warned against 'arrogance in leadership'. Rumsfeld also did not attend the retirement function as he was travelling in Europe on the way to a NATO meeting

His four-year term was marked by clashes with the Pentagon over weapon systems and the number of troops.

He angered civilian officials by persistently advocating the crusader artillery system, even after Rumsfeld cancelled it. He also differed publicly with Rumsfeld and Deputy Defence Secretary Paul D Wolfowitz on the number of troops required to stabilise Iraq.

"You must love those you lead before you can be an effective leader," the New York Times quoted him as saying. "You can certainly command without that sense of commitment, but you cannot lead without it. And without leadership, command is a hollow experience, a vacuum often filled with mistrust and arrogance."

But despite his well-documented differences with the civilian leadership of the Pentagon, the general implicitly admitted the supremacy of civilian authority over army.

"The army has always understood the primacy of civilian control," he said. "In fact, we are the ones who reinforce that principle with those other armies with whom we train all around the world. So to muddy the waters when important issues are at stake -- issues of life and death -- is a disservice to all those in and out of uniform who serve and lead so well."

He warned against cuts in the fighting force. "Our soldiers and families bear the risk and the hardship of carrying a mission load that exceeds what force capabilities we can sustain," he said.

Gen Shinseki also backed former army secretary Thomas E White, who was forced into retirement earlier this year by Rumsfeld, to the hilt. "When they call the roll of principled, loyal, tough guys, you will be at the top of the list," the NYT quoted him as saying of White.

Though he rose through the ranks as a commander of armoured units during the cold war era, he was also the army's expert on peacekeeping operations.

In his 38-year career, Gen Shinseki became the highest-ranking Asian American in the US military history. He received two Purple Hearts for life-threatening injuries in Vietnam.

Vice Chief of Staff Gen John M Keane will serve as acting chief.