Judgment of the Court (Grand Chamber) of 7 June 2005 in Case C-17/03: Reference for a preliminary ruling from the College van Beroep voor het bedrijfsleven Vereniging voor Energie, Milieu en Water and Others v Directeur van de Dienst uitvoering en toezicht energie (Internal market in electricity — Preferential access to the system for cross-border transmission of electricity — Undertaking previously responsible for the operation of services of general economic interest — Long-term contracts existing prior to the liberalisation of the market — Directive 96/92/EC — Principle of non-discrimination — Principles of the protection of legitimate expectation and of legal certainty)