WASHINGTON -- Army Gen. David Petraeus, the four-star general who led troops in Iraq for the past year, will be nominated by President Bush to be the next commander of U.S. Central Command, Defense Secretary Robert Gates said Wednesday.

Gates said he expected Petraeus to make the shift in late summer or early fall. The Pentagon chief also announced that Bush will nominate Army Lt. Gen. Ray Odierno to replace Petraeus in Baghdad.

Central Command oversees the wars in Iraq and in Afghanistan.

"I am honored to be nominated for this position and to have an opportunity to continue to serve with America's soldiers, sailors, airmen, Marines, Coast Guardsmen and civilians," Petraeus said in a brief statement from Baghdad.

At a hastily arranged Pentagon news conference, Gates said the wars in Iraq and Afghanistan, and other problems in the Central Command area of responsibility, demand knowledge of how to fight counterinsurgencies as well as other unconventional conflicts.

"I don't know anybody in the U.S. military better qualified to lead that effort," he said, referring to Petraeus.

Asked if moving Petraeus from the Iraq command could interrupt momentum against the insurgency, Gates said that by waiting until late summer or early fall he hoped to "ensure plenty of time to prepare for a good handoff." He said it also would help that Odierno has had experience as "Petraeus' right-hand man" over the last year.

If confirmed by the Senate, Petraeus would replace Navy Adm. William Fallon, who abruptly stepped down in March after a magazine reported that he was at odds with President Bush over Iran policy. Fallon said the report, while not true, had become a distraction.

Odierno, currently commander of the Army's 3rd Corps based at Fort Hood, Texas, finished in February a 15-month tour as the top deputy to Petraeus in Baghdad. He had been nominated for promotion to full general and assignment as the Army's vice chief of staff, but Gates said the Fallon resignation changed the plan. With Odierno tapped for a return to Baghdad, Gates said Bush will nominate Gates' senior military assistant, Army Lt. Gen. Peter Chiarelli, for the Army vice chief of staff job.

Gates said he had consulted with senior lawmakers, including the chairman of the Senate Armed Services Committee, Sen. Carl Levin, D-Mich., about the nominations, and the defense secretary said he anticipated no Capitol Hill obstacles to confirmation.

Petraeus, 55, is widely hailed by the Bush administration and members of Congress for implementing a new strategy in Iraq, including the deployment of some 30,000 additional troops, that dramatically improved security.

Gates said he expects that Petraeus will make an initial recommendation in late summer on when to resume pulling U.S. forces out of Iraq, following a several-week pause to evaluate the security situation in August.

Central Command, whose headquarters is at Tampa, Fla., is responsible for U.S. military operations throughout the Middle East, Central Asia and the Horn of Africa, and thus oversees the wars in Iraq and Afghanistan.

Fallon relinquished the command March 28 to his top deputy, Army Lt. Gen. Martin Dempsey, and retired from the Navy earlier this month. Dempsey was in the unusual position of having already been nominated to take command of U.S. Army Europe when Fallon bowed out. He appeared to be among those considered as Fallon's permanent replacement, but it now appears he will go to Europe once Petraeus leaves Iraq.

Chiarelli preceded Odierno in Baghdad as the No. 2 U.S. commander and is a former commander of the Army's 1st Cavalry Division.