The challenge of an arbitral award for violation of rules of law relating to the merits of the dispute is admissible when the arbitration agreement predates 2 March 2006, with application of the discipline preceding the amendment to article 829 of the Code of Civil Procedure which came into force on that date, which provided for the challengeability of the award for violation of substantive rules save express contractual exclusion.
The challenge of an arbitral award for violation of rules of law on the merits must specifically indicate the substantive rules which are alleged to have been violated by the arbitral tribunal, a generic complaint of violation of rules of law without identification of the applicable normative precepts being insufficient.
The erroneous reception and assessment of expert conclusions regarding findings of fact which do not involve the application of substantive rules of law falls outside the scope of censurability of the arbitral award upon challenge, as does the alleged lack of correspondence between what was requested and what was pronounced, the latter constituting an error in procedendo not contemplated among the grounds for nullity provided by article 829 of the Code of Civil Procedure.