The Member States and the Community institutions have an obligation of close cooperation in fulfilling the commitments assumed by them under joint competence when they conclude a mixed agreement. That is in particular the position in the case of a dispute concerning essentially undertakings resulting from a mixed agreement which relates to an area in which the respective areas of competence of the Community and the Member States are liable to be closely interrelated. The act of submitting a dispute of this nature to a judicial forum such as an arbitral tribunal established pursuant to Annex VII to the United Nations Convention on the Law of the Sea involves the risk that a judicial forum other than the Court of Justice will rule on the scope of obligations imposed on the Member States pursuant to Community law.
In those circumstances, the obligation of close cooperation within the framework of a mixed agreement involves, on the part of a Member State, a duty to inform and consult the competent Community institutions prior to instituting dispute-settlement proceedings under the Convention.