At the same time they commuted death sentences on six of Abiola's Yoruba kinsmen who were convicted of plotting to overthrow late dictator Sani Abacha, and asked security agencies to compile a full list of political detainees.
Rear-Admiral Victor Ombu told reporters late on Thursday after a two-day meeting of the ruling military council that a small working group would report to military ruler General Abdulsalam Abubakar in a few days after examining different views on restoring democracy.
"In the very near future a fine working paper will be presented in the (commander-in-chief's) next broadcast. In the very near future the way forward will be announced by the head of state," said Ombu on behalf of the Provisional Ruling Council.
He suggested that Abubakar's broadcast could take place at the earliest on Tuesday next week.
A new plan to restore civilian rule is eagerly awaited by Nigerians and the international community, after the oil-producing country of at least 104 million was plunged into political confusion by the sudden death of Abacha and then Abiola a month later.
A team of foreign pathologists began to assemble in Lagos on Thursday to prepare for an autopsy on Abiola, whose death sparked riots in his southwestern home region where his loyalists accused the military of killing him. Up to 45 people have been reported killed in the violence.
"We want to approach the autopsy with an open mind and come to our own conclusions," Canadian doctor James Young told reporters on his arrival at Lagos airport to join the autopsy team.
Abiola's personal doctor, Ore Falomo, said the post-mortem would not be able to take place before Friday evening because of the delayed arrival of two members of the group.
"The burial at the home in Lagos will be able to take place soon after the autopsy is completed and a statement made public on the findings," Falomo told Reuters in Lagos.
A statement from the presidency on Tuesday said Abiola died of an apparent cardiac arrest after being taken ill during a meeting with Nigerian and U.S. officials to discuss conditions for his possible release.
The 60-year-old Moslem tycoon was locked up in 1994 for declaring himself president on the basis of 1993 elections which were annulled by the military as he was poised to win.
Many of the victims of riots in the past two days have been northerners, like Abubakar and most of Nigeria's rulers since independence from Britain in 1960.
The ruling council ordered that death sentences be commuted to jail terms of 20 to 25 years for six prisoners Abiola's southwestern stronghold accused of plotting to topple Abacha. Among the convicts is Abacha's formr deputy, Lieutenant-General Oladipo Diya.