State prosecutor Marie-Helene Heyte called on an appeals court to consider the "compulsory non-handover" of Daniel Derguy, 51, under a European arrest warrant issued by Spain.
He is considered the leader in France of the Basque armed separatist group ETA and is accused of sending a letter bomb from France to a Spanish Basque company in 1994.
If the court decides to agree to the Spanish request, Derguy would be the first French national to be handed over to Spain under such a warrant. A French woman targeted, Aurore Martin, 32, is on the run from arrest.
The "non-handover" procedure allows a court in a European country to refuse a foreign warrant if the suspect can be tried in one of its own courts or if the statute of limitations has expired under its law.
The appeals court in Agen, southwestern France, said it would give a judgment on August 17th.