Angesichts dieser Erwägungen hat der Vergabekontrollsenat des Landes Wien dem Gerichtshof Fragen zur Vorabentscheidung vorgelegt. ###>Since the decision of a contracting authority to withdraw an invitation to tender for a public service contract is subject to the relevant substantive rules of Community law, it has to be concluded that it also falls within the rules laid down by Directive 89/665 in order to ensure compliance with the rules of Community law on public contracts.