The challenge of an arbitration award on grounds of nullity does not give rise to appellate proceedings enabling the court to examine the merits of the arbitral decision directly, but rather to proceedings of limited review aimed at ascertaining whether any of the grounds of nullity set out in art. 829 of the Code of Civil Procedure exist and, only upon a positive finding and declaration of nullity of the award, at re-examining the merits.
A party who has given rise to a ground of nullity of the award may not challenge the award on that ground, pursuant to art. 829, para. 2, of the Code of Civil Procedure.
Pursuant to art. 829, para. 3, of the Code of Civil Procedure, errors of law may be relied upon as a ground of nullity of the award only where such possibility is expressly provided for by law or contemplated by the parties in the arbitration clause or in other instruments prior to the commencement of the arbitration proceedings; the mere provision for a decision according to law is not sufficient.
The contradictory nature of the award relevant under art. 829, No. 4, of the Code of Civil Procedure must arise between the different components of the operative part, or between the reasoning and the operative part, whereas internal contradictions within the reasoning may be relevant only insofar as they make it absolutely impossible to reconstruct the logical and legal reasoning underlying the decision.