A challenge to an arbitral award on grounds of nullity pursuant to Article 829 of the Code of Civil Procedure is a remedy subject to restricted review, available only in respect of specified procedural defects and, as regards non-compliance with rules of substantive law, only where the parties have expressly provided for that right in the arbitration agreement.
The jurisdiction of the arbitral tribunal must be determined by reference to the nature of the dispute as set out in the request for arbitration and the applicable arbitration clause, distinguishing between disputes relating to the corporate relationship and disputes relating to the relationship of collaboration, even where questions relating to the latter constitute factual prerequisites to be ascertained for the purposes of the decision on the principal claim.
In arbitral proceedings, the violation of the adversarial principle within the meaning of Article 829(1)(9) of the Code of Civil Procedure does not constitute a formal defect but a defect of activity, so that for the purposes of the nullity of the award it is necessary to establish a concrete impairment of the right of defence, having the effect of preventing the parties from exercising on an equal footing the procedural rights accorded to them.
The failure to record the expert operations carried out without the intervention of the court does not constitute a violation of the adversarial principle where the operations have in any event been documented, the party-appointed experts participated, and the content of the operations was the subject of subsequent adversarial debate between the experts and between the parties before the decision.
The refusal by the arbitrators to admit certain items of evidence on the ground that they are unsuitable as evidence or that the facts pleaded are superfluous constitutes an assessment falling within the institutional competence of the arbitrators and may not be challenged by way of proceedings to set aside the award on grounds of nullity.
There is no violation of the adversarial principle where the arbitrators carry out assessments of the facts pleaded, the evidence adduced, and the interpretation of documents produced in the course of the proceedings, such activity falling within their institutional competence, save where they base their decision on a point raised of their own motion that was never submitted for the assessment of the parties.
The obligation imposed on arbitrators by Article 823(5) of the Code of Civil Procedure to set out a summary statement of the reasons for the decision, non-compliance with which renders the award null pursuant to Article 829(1)(4) and (5) of the Code of Civil Procedure, may be regarded as unsatisfied only where the reasoning is entirely absent or so deficient as not to permit an understanding of the logical process that led to the arbitral decision, or contains irreconcilable contradictions such as to render the ratio of the decision incomprehensible.
The sanction of nullity provided for by Article 829(1)(11) of the Code of Civil Procedure in respect of an award containing contradictory provisions must be understood as requiring the contradiction to emerge between the different components of the dispositif or between the reasoning and the dispositif, whereas internal inconsistency between different parts of the reasoning may be relevant as a defect of the award only insofar as it renders it absolutely impossible to reconstruct the logical and legal reasoning underlying the decision, by reason of the total absence of reasoning attributable to its functional model.
For the purposes of establishing the defect of failure to adjudicate within the meaning of Article 829(1)(12) of the Code of Civil Procedure, the mere absence of an express ruling on a claim or defence of a party is not sufficient; rather, it must be shown that the provision essential for the resolution of the concrete case has been entirely omitted.
An arbitral award is null pursuant to Article 829(1)(4) of the Code of Civil Procedure where it rules beyond the limits of the claim, recognising an ancillary right on the basis of a ground and in a measure never invoked by the party concerned, in breach of the limits of the devolution of the dispute and of the adversarial principle.
Partial nullity of the award for ultra petita may be declared where the defect affects a part of the award that is severable from the remainder, with the consequence that the rehearing on the merits is limited to the substitution of the unlawful ruling with one consistent with the claim.