In order to establish whether a contractual clause constitutes an arbitration agreement or a mere condition of admissibility, it must be interpreted according to the criteria of articles 1362 et seq. of the civil code: the expressions “shall decide” and “award”, implying the power of the tribunal to render a binding decision, unequivocally indicate the arbitral nature of the clause rather than a simple condition of admissibility.
The distinguishing criterion between arbitration proper and contractual arbitration (arbitrato irrituale) lies in the fact that in the former the parties intend to obtain an award capable of being declared enforceable and of producing the effects provided for by art. 825 of the code of civil procedure, whereas in the latter they intend to entrust the arbitrator with the resolution of the dispute through a strictly contractual instrument, by way of an amicable settlement or a declaratory agreement attributable to their own will.
A plea based on a contractual arbitration (arbitrato irrituale) clause pertains to the merits and not to jurisdiction, unlike a plea of arbitration proper which has a jurisdictional nature, with the result that, if upheld, the court renders a judgment dismissing the claim on the merits and not an order declining jurisdiction.
The plea of contractual arbitration constitutes a plea on the merits in the strict sense and, in eviction proceedings converted to the employment rite under art. 667 of the code of civil procedure, must be raised within the time limit for supplementary submissions.