An action for restitution of undue payment under Article 2033 of the Civil Code has contractual nature, being founded on the non-existence of the obligation performed by one party, and therefore falls within arbitral jurisdiction when an arbitration clause is provided for contractual disputes between parties to the obligatory relationship.
A statutory arbitration clause providing for submission to arbitral procedure of "any dispute, relating to available rights, which should arise concerning the validity, interpretation or performance of the articles or in dependence upon relationships between shareholders or between them and the company," without express provision of limits or exclusions, extends arbitral jurisdiction to disputes whose logical and legal foundation resides in the obligatory relationship established between the parties based on the statutory relationship.
It is irrelevant for purposes of arbitral jurisdiction that the dispute involves interpretation of European directives by national jurisprudence, provided the dispute concerns available rights and has contractual nature, not concerning direct interpretation of European legislation but contractual relationships between the parties.