WASHINGTON, Nov 7: A third US Marine has pleaded guilty in the shooting death of an unarmed Iraqi in April.

As part of a plea bargain, Lance Corporal Tyler A. Jackson, received reduced charges of aggravated assault and conspiracy to obstruct justice.

Cpl Jackson told a court-martial in California on Monday that he knew that the killing was unlawful when it occurred.

Initially charged with seven others with kidnapping and premeditated murder, he avoided the more serious charges as part of a plea agreement to testify against fellow squad members.

A military judge set sentencing for Nov 16.

Seven marines and a Navy corpsman were charged with kidnapping and killing the Iraqi, Hashim Ibrahim Awad, 52, who died of multiple gunshot wounds on April 26, and with covering up the crime.

Another marine, Lance Cpl Jerry E. Shumate Jr, has also been negotiating a plea, defence lawyers said.

At the court-martial on Monday, Corporal Jackson gave testimony about the killing that closely tracked testimony by the two others who have pleaded guilty.

He said the men were on patrol near Hamdaniya searching for Saleh Gowad, an insurgent who repeatedly planted bombs, including one that was thought to have killed four members of a platoon in his company.

The corporal testified that the men kidnapped and killed a man they believed to be Mr Gowad, but who was Mr Awad, staging the scene to make it appear as if there had been a gunfight.