Awards rendered in contractual arbitration may be set aside under Article 808-ter, paragraph 2, nos. 4 and 5 of the Civil Procedure Code when arbitrators fail to comply with rules imposed by parties as conditions for award validity or when the adversarial principle has not been observed in arbitral proceedings.
Arbitrators in contractual arbitration are bound by obligations of confidentiality and non-anticipation of decisions, being unable to reveal in advance to parties the content of decisions they intend to render or evaluations through which they will arrive at award issuance.
In contractual arbitration, the adversarial principle requires that all parties be guaranteed the opportunity to know reasons advanced by opponents and assert their own positions, without parties being informed of evaluative elements and arguments arbitrators intend to adopt as foundations for their judgment.
Violation of confidentiality obligations occurs when arbitrators inform parties, or even one of them, regarding claims they consider well-founded and deserving acceptance or concerning factual elements relevant for decision purposes, effectively anticipating award content.
In the presence of arbitration clauses submitting contractual disputes to arbitrators, counterclaims having the same subject matter as relationships covered by such clauses cannot be brought before ordinary courts but must necessarily be submitted to arbitrators.