Lawyer Irfan Dundar's office said the Istanbul court had slapped a three-year, nine-month sentence on him for "aiding and harbouring a terrorist organisation," but added he would remain free until an appeals court passed a final verdict.

Dundar was arrested after returning from rebel camps in northern Iraq where he had met with top aides of his client, Ocalan.

The 58-year-old Ocalan is the leader of the outlawed Kurdistan Workers' Party (PKK), which has waged a bloody separatist campaign in the mainly Kurdish southeast since 1984 that has claimed some 37,000 lives.

The organisation is listed as a terrorist group by Turkey, the European Union and the United States.

Ocalan was sentenced to death in a high-profile trial in 1999 for treason, but this was commuted in 2002 to a life-term.

He is held in the tiny north-western island of Imrali, where he is the sole prisoner.

In May 2005, the European Court of Human Rights upheld a ruling in favour of Ocalan, saying that he had been unfairly tried by a Turkish court, and urged Ankara to retry him.