Oil exploration concession contracts entered into between Petrobrás and ANP containing an arbitration clause. Dispute concerning the division of an oil field (Campo de Lula) into two separate fields (Campo de Lula and Campo de Cernambi) in connection with a concession contract with an arbitration clause executed by Petrobrás, BG&P, Petrogal, and ANP. Interlocutory appeal challenging an injunction ordering the suspension of arbitration proceedings on the ground that judicial review of non-arbitrability is immediately available, even where the matter has not yet been examined by the arbitral tribunal. The definition of the expression "oil field" is not a matter of mere contractual interpretation, but rather a subject falling within the regulatory powers of ANP, constituting a non-waivable matter. Upholding of the injunction suspending the arbitration proceedings: