Dispute over the division of an oil field (Campo de Lula) into two other fields (Campo de Lula and Campo de Cernambi) in light of a concession contract with an arbitration clause entered into by Petrobras, BG&P, Petrogal, and ANP. Interlocutory appeal challenging an injunction ordering the interruption of arbitration proceedings on the grounds of the immediate possibility of judicial review of non-arbitrability, even though the matter had not yet been examined by the arbitral tribunal. Definition of the expression "oil field," which is not a matter of mere contractual interpretation but rather a subject circumscribed by ANP's regulatory power, constituting a non-waivable matter. Upholding of the injunction suspending the arbitration proceedings: