The challenge proceedings against an arbitral award pursuant to article 827 of the Code of Civil Procedure do not constitute appellate proceedings but rescissory proceedings with limited grounds for review, in which the challenger may seek exclusively a declaration of nullity of the award for the causes exhaustively set out in article 829 of the Code of Civil Procedure, and only following determination of nullity does the rescissory phase open with examination of the merits.
Arbitral proceedings commence with the written acceptance of the appointment by the arbitrators pursuant to article 813 of the Code of Civil Procedure, from which moment the time limits for rendering the award begin to run, irrespective of the time elapsed between the nomination of the arbitrators and their formal acceptance.
Article 813-bis of the Code of Civil Procedure concerning substitution of an arbitrator for omissions or delays refers exclusively to conduct subsequent to the constitution of the arbitral tribunal and is not relevant for the purposes of the validity of the award in respect of delays antecedent to acceptance of the appointment.
Forfeiture for expiry of the time limit pursuant to article 820 of the Code of Civil Procedure cannot be relied upon as a ground for nullity of the award if the interested party has not notified the other parties and the arbitrators, before deliberation of the award, of the intention to rely on the forfeiture pursuant to article 821 of the Code of Civil Procedure.
In case of doubt, the arbitration agreement is to be interpreted extensively in the sense that arbitral jurisdiction extends to all disputes arising from the contract or relationship to which the agreement refers, pursuant to article 808-quater of the Code of Civil Procedure.
The signature of the majority of arbitrators is sufficient for the validity of the award if accompanied by a declaration that it was deliberated with the participation of all and indication of the reasons why the other arbitrators were unwilling or unable to sign it, in accordance with article 823, paragraph 7, of the Code of Civil Procedure.
Nullity of the award for violation of the adversarial principle pursuant to article 829, paragraph 1, No. 9, of the Code of Civil Procedure requires demonstration of an actual impairment of the possibility to adduce evidence and contradict, with verification of the proper establishment of adversarial proceedings and the subsistence of prejudice to the right of defence.
Nullity of the award for contradictory provisions pursuant to article 829, paragraph 1, No. 11, of the Code of Civil Procedure requires an irreconcilability between parts of the operative part or between the operative part and reasoning such as to render impossible the reconstruction of the ratio decidendi, whereas internal contradictoriness in the reasoning is relevant only when it results in the absolute impossibility of reconstructing the logical-legal reasoning of the decision.