Central Command chief General Tommy R Franks, who successfully planned and commanded the American-led wars in Iraq and Afghanistan, has decided to retire after 36 years in service.

The White House has not named a replacement, but one likely candidate is Lieutenant General John Abizaid, who was Franks's deputy at Camp As Sayliyah during the Iraq War.

Praising Franks while announcing his retirement plans, Secretary Donald H Rumsfeld said, "He has served our country with great distinction. I consider myself privileged to have worked so closely with him over these many months."

Jim Wilkinson, director of strategic communications at Central Command, said Franks's status would have no effect on the work of US and coalition forces in Iraq.

"You can bet that Gen Franks will spend every remaining minute of his time ensuring that the troops in the field have what they need," Wilkinson said.

The 57-year-old native of Midland, Texas, was commissioned a second lieutenant in 1967 as a graduate of the Artillery Officer Candidate School at Fort Sill, Oklahoma, and in short order he was serving with the 9th Infantry Division in Vietnam.

After the Vietnam War, Franks intended to leave the military but stayed on when selected for the army's 'Bootstrap' degree completion programme for promising officers.

He attended the University of Texas at Arlington.