The waiver of challenge to an arbitral award is equivalent to a waiver of action and results in the award becoming res judicata, producing immediate effect without requiring acceptance by the other party, unlike waiver of procedural acts which requires acceptance pursuant to article 306 of the Code of Civil Procedure.
In interpreting a waiver of challenge to an arbitral award, the generic clause “with costs set off” cannot be considered a condition precedent to the effectiveness of the unilateral act, and must be interpreted as a mere request to the counterparties and to the court in consideration of the waiving party’s procedural conduct.