Zacarias Moussaoui, the only person to be convicted in connection with the 9/11 attacks, had requested to serve the rest of his life sentence in his native country instead of a prison in Colorado.
The accused mastermind of the plot, Khalid Shaikh Mohammed, appeared at a session as the agreement was disclosed. A sentencing hearing could begin next year.
A military judge allowed the lead defense lawyer to leave next month, but his successor has not yet received the security clearance she needs to take over.
A guide to the prosecution of five men accused of conspiring in the Sept. 11, 2001, hijackings that killed nearly 3,000 people in New York, at the Pentagon and in Pennsylvania.