Indonesian militant Umar Patek has been found guilty of murder and sentenced to 20 years in prison for his role in the 2002 Bali bombings and other terrorist attacks.

A panel of judges handed down the ruling during a marathon 11-hour verdict reading.

Patek had admitted to mixing explosives for some of the bombs that killed more than 200 people, including 88 Australians, in Bali.

But he insisted his role in the attacks was minimal and said he had argued against attacking in Bali because it was not an active war zone.

He was also found guilty of weapons and conspiracy charges over a terrorist training camp in Aceh in 2009, and for mixing explosives for a series of Christmas Eve attacks on churches in 2000.

Patek sat motionless and staring at the floor for most of the 11-hour reading of the verdict and showed no reaction when the judge announced his 20-year sentence.

The maximum penalty is death but the prosecutors requested a life sentence.

The 20-year sentence is the same one handed to Schapelle Corby for smuggling marijuana, and, with good behaviour, Patek could be out in less than 15 years.

Patek fled to Pakistan in 2010 using a false passport and was detained in the town of Abbottabad just months before Osama bin Laden was killed by US troops there last year.

An FBI agent told the trial there was intelligence that Patek went to meet Bin Laden and revive the terrorist campaign in South-East Asia.

Patek's lawyer said his client had shown remorse for his actions.

"Umar Patek was not angry about this sentence, but he felt sad," he said.

"He has admitted all his actions and he was honest in this trial.

"He admitted everything and concealed nothing, but he also gave reasons why he did it.

"It should be taken into consideration in order to alleviate the prison sentence imposed."