VILSECK, Germany - A U.S. army soldier convicted of murder in the 2007 killings of four bound and blindfolded Iraqis was sentenced Thursday to life in prison.

Master Sgt. John Hatley, 40, also will have his rank reduced to private, forfeit all pay and receive a dishonourable discharge, a jury of eight army officers and noncommissioned officers decided. He has the possibility of parole after serving 20 years.

The sentence came a day after Hatley was found guilty of premeditated murder and conspiracy in the execution-style killings of the detainees.

He was found not guilty of premeditated murder in a separate January 2007 incident in which a wounded Iraqi insurgent was shot and killed.

In an emotional closing statement earlier Thursday, the career soldier urged the jury to let him complete 20 years of military service.

Hatley, who recently had a knee surgery, limped to the stand to urge the panel to grant him six more months of service so that he could reach the milestone.

"I've served my country for half my life, which I think is the most honourable profession in the world," he said. "I served America with the best men our great country has to offer. And they are so many. My soldiers are like my sons and there's nothing I wouldn't do for them."

Prosecution lawyer John Riesenberg had argued the case was about how Hatley used his reputation to lead his soldiers down "the brutal path to murder."

"This is among the most colossal failures of leadership," Riesenberg said. Defence lawyer David Court said Hatley was not the evil person the defence was portraying him to be.

"You have to think about what they (these men) were going through (in Iraq) to judge fairly. He loved his soldiers too much, that was his crime," Court said.

According to testimony this week and at previous courts-martial, four Iraqis were taken into custody in spring 2007 after an exchange of fire with Hatley's unit.

Hatley's lawyer has argued that army prosecutors based their case on assumptions and conflicting testimony from this week and other courts-martial, saying there was no physical evidence that anyone was shot or killed. The bodies of the victims have never been found.

Previous courts-martial related to the incident resulted in murder convictions of two other soldiers who served in Hatley's unit.