Paper Title
Challenges in Public Procurement Contract Execution

For the functioning of a public procurement system the performance of the public procurement contract represents a critical part. The extent to which contracting authorities are allowed to amend a procurement contract after signature is one of the greyest areas in European public procurement. For the first time a EU Directive on public procurement regulates explicitly the contract performance. This paper aims at to present the challenges that might appear during the execution phase of a public procurement contract. Also, the present paper will provide an assessment of the rulings of the Court in this matter. Index Terms - Amendments to Public Procurement Contract, Execution Phase, Retender, Substantial Modification