In the case of contractual arbitration (arbitrato irrituale), the question of the existence of a valid arbitration agreement concerns the admissibility of the claim and constitutes a preliminary issue on the merits, rather than a question of jurisdiction, and must be decided by a judgment dismissing the claim on the merits where the objection is upheld, since the parties have contractually waived recourse to State judicial protection in favour of a contractual resolution of the dispute pursuant to Article 808-ter of the Code of Civil Procedure.
An arbitration clause referring to contractual arbitration (arbitrato irrituale) any dispute concerning the interpretation, performance or termination of a contract also encompasses claims for contribution between the contracting parties based on the alleged breach of obligations arising from the same contract, as they relate to the performance of the contractual relationship which is the subject of the arbitration agreement.