His lawyer Maritxu Paulus-Basurco said she would appeal the ruling by the court in the southern city of Toulouse.
Ramos, who was on the run after being sentenced in Spain in 1986 to 51 years in prison for his role in deadly attacks, membership of an armed group and possessing weapons, was arrested in Ciboure in southwestern France in March this year.
He had been released under supervision in Spain due to ill-health. Spanish authorities say he flouted the conditions by residing in France and skipping an obligation to report regularly to them.
The Basque separatist movement is blamed for 829 deaths during a four-decade campaign of shootings and bombings for an independent homeland in northern Spain and southwestern France.
It is classed as a terrorist group by the European Union and the United States.
The group announced in October 2011 that it was giving up its armed struggle.