(Updates with hearing held, changes byline and dateline, previous WASHINGTON)
By Tom Ramstack
FORT MEADE, Md., Aug 11 (Reuters) - A military court heard arguments on Monday on removing one of five men charged in the Sept. 11, 2001, attacks on the United States from a joint trial because of his mental condition.
Prosecutors are seeking to reverse a decision by the judge, Army Colonel James Pohl, ordering a separate trial for Ramzi bin al-Shibh, a 42-year-old Yemeni imprisoned at Guantanamo Bay, Cuba.
In his July order, Pohl cited issues with al-Shibh's competency and a potential conflict of interest in his defense team. Prosecutors say al-Shibh might be delusional but is competent to stand trial.
Prosecutor Clay Trivett argued that al-Shibh should be tried with the other four defendants, including suspected ringleader Khalid Sheikh Mohammed.
"They're all charged with an identical conspiracy charge," Trivett said, adding that further delays could interfere with a speedy trial required by the U.S. Constitution.
Federal law allows separate trials for multiple defendants in a single criminal case when a joint trial would be unfair to the other accused because of their different interests.
Al-Shibh was forcibly removed from hearings in December after shouting about "torture" and a "secret CIA prison."
His attorneys told the judge he complained about "vibrations" and noise that make him unable to sleep in his cell at the U.S. prison at Guantanamo Bay.
Guards denied the claims. Military psychiatrists have been unable to agree on al-Shibh's mental health.
He is accused of wiring money and passing on information from al Qaeda leaders to the hijackers who slammed airliners into New York's World Trade Center, the Pentagon and the Pennsylvania countryside, killing 2,976 people.
Al-Shibh's attorney, James Harrington, did not dispute the judge's order but sought more time to consult with his client.
A second defendant, Mustafa Ahmed al-Hawsawi, a 46-year-old Saudi, is seeking a separate trial. He has argued that his alleged role was smaller than his co-defendants' and joint prosecution would violate his rights to a fair trial and to confront accusers.
The defendants could be executed if convicted of charges that include mass murder, terrorism and hijacking.
The Guantanamo Bay hearing was monitored by closed-circuit television at Fort Meade, Maryland. Pohl canceled a Tuesday session and the hearing will resume on Wednesday. (Reporting by Ian Simpson; Editing by Mohammad Zargham and Jim Loney)