The European Commission (Commission) has sent a reasoned opinion to Greece concerning a tendering procedure conducted by the Company for Water Supply and Drainage of Athens for the award of a drainage contract and the extent to which this complied with the Utilities directive (2004/17/EC). Concerns have been raised regarding the acceptance of an offer from the preferred bidder despite the fact that the terms of its bank guarantee did not comply with the term in the original call for tenders. The contracting authority also accepted the offer of the second lowest bidder, although the Commission considers that there were problems with the supporting documents provided.