The 62-year-old Ocalan has been serving a life sentence since 1999 for the campaign for self-rule waged by his outlawed Kurdistan Workers' Party (PKK), considered a terrorist group by Ankara and much of the international community.

Ocalan applied for Ankara to reopen his case, invoking a 2005 ruling by the European rights court which found that his original trial had been flawed and suggested a retrial as a way to offer him redress.

But the court noted that the Council of Europe's 47-member committee of ministers had expressed satisfaction with the steps taken by Turkey since the 2005 ruling to improve Ocalan's conditions.

Ocalan's original death sentence was commuted to life in prison as Turkey abolished capital punishment as part of EU-sought reforms.

He was the sole inmate at a prison on the island of Imrali until last November when Ankara transferred five other prisoners to the facility, in response to protests from Council of Europe's anti-torture committee.

Complaints by Ocalan over his new prison conditions sparked major demonstrations in the majority Kurdish southeast of Turkey last year, resulting in three deaths.