The objection based on a contractual arbitration (arbitrato irrituale) clause contained in the articles of association is procedural in nature and constitutes a matter of jurisdiction, subject to the regime of procedural preclusions. Such objection must be raised by the interested party, on pain of forfeiture, in the statement of defence duly filed pursuant to Article 166 of the Code of Civil Procedure, with the consequence that the potestas iudicandi vests in the ordinary court seised in the event of late appearance by the defendant. The objection of contractual arbitration (arbitrato irrituale) cannot be raised by the court of its own motion.