The EU Court EU Court in Luxembourg created the concept of "implied powers". This was to give the EU the ability (competence) to negotiate international treaties in areas where the EU has the ability to control laws within the EU (internal competence to legislate). See AETR AETR.
The future
The Convention on the Future of Europe proposes "implied power" a general rule by giving the European Union legal personality. Legal personality will allow the EU to represent the Member States in negotiations with non-EU countries.