GUANTANAMO BAY NAVAL BASE, Cuba (AP) -- A former Maryland resident pleaded guilty Wednesday to helping al-Qaida plot attacks from his native Pakistan, reaching a plea deal with the U.S. government that limits his sentence but that his lawyers say could put him and his family in jeopardy.

A lawyer entered the plea on behalf of Majid Khan at the U.S. base in Cuba. Asked by the judge if he understood the plea, Khan answered in English, "Yes, sir."

The plea deal, the first reached by one of the military's "high-value" detainees at Guantanamo, says Khan, 32, could serve less than 19 years in prison as long as he provides "full and truthful cooperation," to U.S. authorities building cases against other prisoners, according to Army Col. James Pohl, the military judge.

His attorneys wanted details of the plea deal kept confidential. Wells Dixon, one of his civilian lawyers, said Khan feared for the safety of family members in the United States and abroad. "There is a specific, historical basis for the concern," he told the judge.

Pohl rejected the request, saying the fact that he had agreed to cooperate was already in the public domain.

Khan had faced up to life in prison if convicted on all charges, which include conspiracy, murder and spying. Documents released before Wednesday's hearing had said the pretrial agreement capped his sentence at 25 years. The judge said his sentencing would be delayed for four years, giving him time to provide testimony against other detainees, and that the Convening Authority, the Pentagon legal official who oversees the tribunals, would not approve a total sentence that exceeds 19 years.

Khan would get credit for time served until his sentencing but not for the nine years he has already been in custody. The judge told him that there was nothing in the agreement that specificially prevents the U.S. from continuing to detain him after he completes his sentence, though there are no indications that would happen.

"I am making a leap of faith here sir," Khan told the judge in response. "That's all I can do."

Khan is the seventh Guantanamo prisoner to be convicted of war crimes and he is considered the most significant. He is the first prisoner who was held in clandestine CIA custody overseas - where prisoners endured harsh treatment that lawyers and human rights groups have labeled torture.

Andrea Prasow, a Human Rights Watch lawyer who was at the hearing as an observer, said Khan could have gotten a longer sentence if convicted at trial, but the U.S. government now gets the benefit of his assistance and can avoid confronting allegations that Khan and other prisoners were tortured. "They get a lengthy sentence, minimum 19 years with cooperation, and no one has to hear about what happened to him when he was in CIA custody," she said outside the court.

There were four previous plea bargains at Guantanamo and Prasow expects more. "There is a stronger incentive to plea bargain in Guantanamo if you have no idea how long you will be held or if you will ever be released or if you will ever get a fair trial," she said.

Khan's appearance Wednesday, dressed in a dark blazer and tie and with neatly trimmed hair and beard, was the first time he has been seen in public since his capture in March 2003.

Prosecutors said Khan plotted with the self-proclaimed mastermind of the Sept. 11 attack, Khalid Sheikh Mohammed, to blow up fuel tanks in the U.S., to assassinate former Pakistani President Gen. Pervez Musharraf and to provide other assistance to al-Qaida.

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 at 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-Qaida because of his fluent English and familiarity with the U.S. Prosecutors say that at one point he discussed a plot to blow up underground fuel storage tanks.

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-Qaida 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 more.

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