In arbitration clauses that refer all disputes to arbitral jurisdiction with express reservation to ordinary jurisdiction of those relating to breach of contractual obligations, disputes concerning reduction of consideration aimed at avoiding breach fall within the jurisdiction of the ordinary courts.
An action for reduction of contractual consideration, even when brought after breach, essentially constitutes a dispute aimed at excluding breach that has already materialized regarding the payment obligation and therefore falls within the reserved jurisdiction of ordinary judicial authority when this is provided for disputes relating to contractual breaches.
Claims that are merely consequential to that of termination for breach are included in the clause reserving jurisdiction to ordinary judicial authority when this excludes from arbitral jurisdiction disputes relating to breaches of contractual obligations.
In arbitration clauses with reservation of jurisdiction to ordinary courts for specific disputes, the interpretation of the scope of application of the reservation must be carried out by evaluating the substance of the claims made rather than their formal qualification.