WASHINGTON -- Army General Tommy Franks, who led U.S. forces in two wars in two years in Afghanistan and Iraq, has decided to retire, a U.S. military official said Thursday.

The date Franks, 57, will leave the service "is one of the things he has to decide" in conjunction with Secretary of Defense Donald Rumsfeld, said the official, who asked not to be identified. No successor has been named.

As commander-in-chief of the us central command, Franks successfully led U.S. and coalition forces in wars that ousted the Taleban regime from Afghanistan in 2001, and the regime of Saddam Hussein in Iraq in April, AFP reported.

He brought both conflicts to a swift conclusion with bold and unconventional tactics that initially drew fire from critics but in the end proved effective.

An artillery officer by background, Franks made dramatic use of U.S. special operations forces in both wars, and gambled in favor of speed of movement over the massing of overwhelming force to capture Baghdad in only three weeks. Rumsfeld, who leaned on him to produce more imaginative war plans, hailed Franks as "a truly outstanding professional military officer who performed his critically important tasks just about as well as they could have been performed."

The secretary was reported to have offered Franks the position of chief of staff of the army, but the general was intent on retiring after 36 years in uniform, fulfilling a long-time promise to his wife, Cathy.

"He chooses to retire," Cathy Franks said in a recent interview with the St. Petersburg times.

The fame of his wartime conquests will to open doors to offers of lucrative book deals, speaking engagements, and other post-military carrier opportunities should he choose to pruse them. But his exploits may shadow him as well.

He already has been targeted by a war crimes law suit filed by a Belgian attorney who alleges that soldiers under his command fired on ambulances, did not show due care for avoiding civilian casualties and failed to protect Iraq's cultural heritage.

The Belgian government moved to quash the suit, but the attorney is appealing Franks' retirement did not come as a surprise.

At Rumsfeld's request, he already had stayed on for an extra year to lead the war in Iraq, and he was due to turn over command of U.S. forces in the Persian Gulf at the end of June.

During a trip to the region late last month, Rumsfeld met Franks' top generals to discuss their future, but so far has given no hint as to who will replace Franks.

Among those mentioned as possible successors are army Lieutenant General John Abizaid, the deputy commander of the central command, and army Lieutenant General David McKiernan, the commander of the ground forces during the war in Iraq.

His successor will assume command at a time of growing concerns about the unsettled security situation in Iraq where a tide of lawlessness and jockeying for power by ethnic and religious factions has eroded public patience with a U.S.-led occupation.

He also will inherit an unfinished war on terrorism.

Osama bin Laden, the alleged mastermind of the September 11, 2001 attacks on the United States, remains at large. His Al-Qaeda terrorist network has been blamed for suicide attacks May 12 that killed 34 people in Saudi Arabia.