Updated

A Pakistani man who attended a suburban Baltimore high school and is accused of plotting with the self-proclaimed mastermind of the Sept. 11 attack to blow up fuel tanks in the U.S. would serve no more than 25 years in prison under a plea deal, according to military documents released Tuesday.

Majid Khan would plead guilty to charges that include conspiracy, murder and attempted murder for a range of post-Sept. 11 plots, making him the first of what U.S. officials deem the "high value" prisoners at Guantanamo Bay to be convicted.

Details of the plea deal have not been disclosed, but a sentencing document released before Khan's Wednesday hearing sets out the broad outlines. A jury of military officers could sentence Khan to 25 to 40 years in prison, but the Convening Authority, a Pentagon legal official who oversees the tribunals, would agree not to approve a sentence that exceeds 25 years.

Since the agreement has not been released, any exact sentence specified by the plea agreement is not yet known, and it could be less than the maximum. Also unknown is if Khan will be required to testify against fellow prisoners such as Khalid Sheikh Mohammed, the self-proclaimed mastermind of the Sept. 11 attack.

Al-Arabiya TV, citing unidentified sources, reported that Khan would serve about 15 years under the deal and that military authorities already eased the conditions of his confinement at Guantanamo, where he has been held in the top-secret Camp 7 since September 2006.

His lawyers have declined comment.

Khan's actual sentencing would be postponed for four years if he does not comply with the terms of his agreement and the military would have the option of sentencing him to any longer sentence imposed by a jury.

The guilty plea, which would be official if he enters it Wednesday, is a significant milestone for the Guantanamo war crimes tribunals. It could speed up the pace of the long-stalled trials if he can provide crucial testimony about the inner workings of Al Qaeda, said Karen J. Greenberg, director of the Center on National Security at Fordham Law School.

"He is someone who in a variety of countries is tied to the highest levels of Al Qaeda," Greenberg said. "Getting a plea from someone like this solves the problem of how to try these guys without using evidence obtained through torture."

Khan, who turned 32 Tuesday, has been in U.S. custody since March 2003, when Pakistani forces raided his family's home in Karachi, that country's biggest city. He was turned over to the CIA and held in secret confinement overseas until he was transferred to Guantanamo along with Mohammed and other high-value detainees.

He has not been seen in public since he was captured. In a transcript of a hearing before a panel of military officers in 2007, he denied being a member of Al Qaeda and said he had twice attempted suicide to protest the harsh conditions of his confinement.

Khan moved to the U.S. with his family in 1996 and was granted political asylum. He graduated from Owings Mills High School in suburban Baltimore and worked several office jobs as well as at his family's gas station.

Military prosecutors say he traveled in 2002 to Pakistan, where he was introduced to Mohammed as someone who could help Al Qaeda because of his familiarity with the U.S.

Prosecutors say that at one point he discussed a plot to blow up underground fuel storage tanks.

Khan also allegedly volunteered to assassinate former Pakistani President Pervez Musharraf and recorded a "martyr's video," donning an explosive vest and waiting for the leader to show up at a mosque, according to military documents.

Prosecutors say Khan later traveled with his wife, Rabia, to Bangkok, Thailand, where he delivered $50,000 to the Southeast Asian terror group Jemaah Islamiyah, an Al Qaeda affiliate, to help fund the Aug. 5, 2003, suicide bombing of the J.W. Marriott hotel in Jakarta, Indonesia. The attack killed 11 people and wounded at least 81 others. A California woman who was wounded in the attack is at Guantanamo this week to observe the court hearing Wednesday.

If Khan's plea deal is finalized, he would be the seventh prisoner convicted by a military tribunal since the prison opened in January 2002. Four other prisoners have been convicted in plea bargains and two have been convicted at trials.

The U.S. military holds 171 prisoners at Guantanamo, and officials have said about 35 could face war crimes charges.

"The lesson of this plea deal is that detainees who are charged with crimes are better off than detainees who aren't," said David Remes, a veteran detainee lawyer. "If you're charged, you enter a plea deal. At least you'll know you'll be released sometime, and you have some idea when. But if you're not charged, you don't know if you'll ever be released."