Since in arbitration it is procedural in nature and raises an issue of jurisdiction, the objection based on the arbitration agreement must be raised, on pain of forfeiture, in the first defensive pleading.
An arbitration clause does not exclude the jurisdiction of the ordinary court to issue a payment order, but, where the jurisdiction of the arbitrators is invoked in the opposition proceedings, the court must revoke the order and decline jurisdiction in favour of the arbitrators.
Rules corresponding to art. 50 cod. proc. civ. on the resumption of proceedings apply to the relationship between arbitration and court proceedings.