Pursuant to art. 816-quinquies co. 1 cod. proc. civ., voluntary intervention and the joinder of a third party in arbitration proceedings are permitted only with the agreement of the third party and of the parties and with the consent of the arbitrators.
Dependent adhesive intervention in arbitral proceedings, pursuant to art. 816-quinquies co. 2 cod. proc. civ., is always permitted without the need for the agreement of the parties or the consent of the arbitrators, in conformity with the provisions of art. 105 co. 2 cod. proc. civ.
Pursuant to art. 816-quinquies co. 3 cod. proc. civ., succession by particular title to the right in dispute in arbitral proceedings relating to a public service concession presupposes the actual completion of the assignment also as against the assigned contracting party; where the concession agreement makes the transfer conditional upon formal approval by the conceding authority, the transfer of the branch of business inclusive of the concession is not perfected, as against the public body, until such approval has been given, by reason of the principle of intuitus personae which characterises the concession relationship.
A dependent adhesive intervener in arbitral proceedings does not have autonomous standing to challenge the arbitral award, being entitled only to join the challenge brought by the assisted party; the inadmissibility of the grounds of challenge raised by the assisted party entails that the intervener’s grounds on the merits are subsumed.
Article 829 co. 2 cod. proc. civ. (in the text predating the reform introduced by d.lgs. 40/2006), applicable to arbitral proceedings commenced after the coming into force of the new regime but pursuant to an agreement entered into previously, permits, in the silence of the parties, the challenge of the arbitral award for violation of rules of law relating to the merits of the dispute, unless the parties have authorised the arbitrators to decide according to equity or have declared the award not subject to challenge.