TITJUR EVN and Wienstrom Opinion of Mr Advocate General Mischo delivered on 27 February 2003. # EVN AG and Wienstrom GmbH v Republik Österreich. # Reference for a preliminary ruling: Bundesvergabeamt - Austria. # Directive 93/36/EEC - Public supply contracts - Concept of the most economically advantageous tender - Award criterion giving preference to electricity produced from renewable energy sources - Directive 89/665/EEC - Public procurement review proceedings - Unlawful decisions - Possibility of annulment only in the case of material influence on the outcome of the tender procedure - Illegality of an award criterion - Obligation to cancel the invitation to tender. # Case C-448/01.