Zacarias Moussaoui, the only person charged in the United States in the Sept. 11, 2001, attacks, will plead guilty at a court hearing on Friday, a US District Court said on Wednesday.

US District Judge Leonie M. Brinkema in Alexandria, Virginia, has scheduled to meet with Moussaoui at a hearing on Friday, at which Moussaoui is expected to plead guilty.

Moussaoui is charged with six counts of conspiracy in relation to the Sept. 11 attacks that killed nearly 3,000 people in New York and Washington.

It is not known if Moussaoui would plead guilty to all or only some of the charges, four of which could bring him the death penalty.

Moussaoui, who was arrested in August 2001 on immigration charges, was indicted in December 2001 but his trial has been delayed three times. For most of the past two years, the case has been tied up in the appellate courts in a dispute over Moussaoui's access to key al Qaeda witnesses.

Moussaoui tried to plead guilty in 2002, claiming he had detailed knowledge of the Sept. 11 plot, but reneged a week later saying that although he was an al Qaeda member, he had no advance knowledge of the hijackings. His mental state has been an issue in the case ever since.

Judge Brinkema reportedly ruled that Moussaoui is mentally competent to admit guilt, after a meeting with him Wednesday.