An objection relating to a contractual arbitration clause (arbitrato irrituale) pertains to the merits, inasmuch as the arbitral pronouncement is of a contractual and not jurisdictional nature, and the arbitration agreement is configured as an agreement for renunciation of judicial action and of the jurisdiction of the State, with consequent inapplicability of the rules laid down for arbitration, including Article 819-ter of the Code of Civil Procedure.
The objection by which there is alleged the existence of an arbitration clause for contractual arbitration does not raise a question of jurisdiction of the judicial authority, but contests the proposability of the claim by reason of the contracting parties having chosen contractual resolution of the dispute, renouncing jurisdictional protection.
An objection based on an arbitration clause for contractual arbitration does not have a procedural but a substantive nature, and introduces a preliminary question of merit in relation to the existence or otherwise of the renunciation of jurisdictional protection.
The decision by which the judge, in presence of an objection based on an arbitration agreement for contractual arbitration, closes or does not close the proceedings before him is to be considered as a decision pronounced on a preliminary question of merit, inasmuch as it pertains to the validity or interpretation of the arbitration agreement or arbitration clause, with the consequence that such pronouncement is appealable, and where appeal is not brought, res judicata is formed.