The ELA claimed scores of attacks from the mid-1970s to the mid-90s

The three men and one woman face sentencing later in the week. A fifth defendant was cleared of all charges.

The judge said the guilty four had played a secondary role in 42 bombings and 48 murder attempts since 1983 by the People's Revolutionary Struggle.

The four, who may appeal the judgment, face a maximum of 25 years in jail.

They were not convicted of the more serious charges of actually orchestrating or carrying out any of the attacks, in which one policeman died, due to a lack of evidence.

A statute of limitations prevented them from being charged in connection with attacks more than 20 years old.

Convicted: Christos Tsigaridas, Angeletos Kanas, Irini Athanassaki, Costas Agapiou Acquitted: Michalis Kassimis

They also escaped sentences under Greece's anti-terrorism legislation because the court found that ELA suspended operations in 1995 - six years before the law came into force.

The trial was held under tight security in Greece's largest high-security prison of Korrydallos outside Athens by a special anti-terrorism tribunal without a jury.

It was part of a police crackdown on radical groups in the face of intense international pressure to improve security ahead of the 2004 Olympic Games in Athens.

My client was the victim of a politically-motivated police investigation Spyros Fitrakis Lawyer for Costas Agapiou (above)

Lawyers for Athanassaki, Agapiou and Tsigaridas said their clients would appeal against the decision, reported AFP news agency.

"It's a totally mistaken and unjust decision... my client was the victim of a politically-motivated police investigation," said Spyros Fitrakis, the attorney representing Agapiou, according to the agency.

All the suspects except Tsigaridas, who is an architect, had denied any involvement with the group.

The radical left-wing ELA was formed in 1975, one year after the fall of Greece's military junta.