WASHINGTON: US prosecutors have reached a deal with 9/11 mastermind Khalid Sheikh Mohammed, the Pentagon said Wednesday, reportedly involving a guilty plea in exchange for avoiding a death penalty trial.

The agreements with Mohammed and two other accused moves their long-running cases toward resolution. These have been bogged down in pre-trial maneuverings for years while the defendants remained held at the Guantanamo Bay military base in Cuba.

A Pentagon statement said no details of the deal would be immediately made public at this time, but the New York Times reported that Mohammed, Walid bin Attash and Mustafa al-Hawsawi had agreed to plead guilty to conspiracy in exchange for a life sentence instead of a trial after they could get the death penalty.

Such a proposal was detailed by prosecutors in a letter last year but divided the families of the nearly 3,000 people killed in the September 11, 2001 attacks, with some still wanting the defendants to face the ultimate penalty.

Much of the legal jousting surrounding the men’s cases has focused on whether they could be tried fairly after having undergone methodical torture at the hands of the CIA in the years after 9/11 — a thorny question that the plea deals help avoid.

Mohammed was regarded as one of Al-Qaeda chief Osama bin Laden’s most trusted and intelligent lieutenants before his March 2003 capture in Pakistan. He then spent three years in secret CIA prisons before arriving in Guantanamo in 2006.

The trained engineer — who has said he masterminded the 9/11 attacks “from A to Z” — was involved in a string of major plots against the United States, where he had attended university.

In addition to planning the operation to bring down the Twin Towers, Mohammed claims to have personally beheaded US journalist Daniel Pearl in 2002 with his “blessed right hand,” and to have helped in the 1993 World Trade Center bombing that killed six people.