A declaration of *lis pendens* in an arbitral award regarding claims already subject to ordinary court proceedings does not constitute nullity of the award under article 829 of the Code of Civil Procedure when such declaration is inadmissible for lack of standing, given that the pronouncement is devoid of legal effects and may be considered *tamquam non esset*.
The challenge of an arbitral award for nullity pursuant to article 829 of the Code of Civil Procedure is characterised as a limited form of appeal, admitted exclusively for procedural defects (*vizi in procedendo*) and for non-observance of rules of law specifically provided for by the statute, without permitting a general review on the merits of the arbitral decision.
Nullity of an arbitral award for lack of reasoning may be declared only where there exists a deficiency such as to constitute substantial non-existence thereof, occurring when there is an absolute impossibility of reconstructing the logical-legal reasoning of the decision due to total absence of reasoning referable to its functional framework.
Nullity of an arbitral award for contradictory reasoning arises not in cases of mere contradiction between points of the reasoning or of its insufficiency, but only when there exists contradiction between the rulings of the operative part (*dispositivo*) or between the reasoning and the operative part such as to prevent comprehension of the *ratio decidendi*.
The suspension of arbitral proceedings pending judgment on the challenge of a previous award is left to the discretionary assessment of the arbitrator pursuant to article 819-bis, paragraph 2, of the Code of Civil Procedure, which refers to the regime of discretionary suspension under article 337, paragraph 2, of the Code of Civil Procedure.