An arbitration clause constitutes an autonomous contract separate from the principal agreement in which it is included, endowed with its own identity and effectiveness, such that neither the invalidity nor the termination of the substantive contract results in the nullification of the arbitration agreement, unless there is non-existence of the agreement to which it is accessory or direct nullification of the clause itself.
In arbitration agreements containing merely potestative conditions for access to the arbitration procedure, where the occurrence of the condition is prevented by the omissive conduct of the party having an interest contrary to its realisation, the fiction of occurrence provided for by article 1359 of the Civil Code applies, with the consequent effectiveness of the arbitration clause.