The Technical Assistance to the Serbian Railways Infrastructure (SRI) and other relevant authorities involved in operation of a Project Implementation Unit ("PIU") will support implementation the Rail Corridor X modernization project. Railway Corridor X modernization project is planned to be financed by Banks (EIB, EBRD) and European Commission and the Republic of Serbia. The aim of the Technical assistance to support the PIUthroughout the project phases preceding the launch of works and supervision tenders, including the support in obtaining necessary construction permit(s) and reviews; through the procurement procedures as such and support the PIU through the entire implementation phase, covering, but not limited to assistance in all contractual matters; appliance of EU relevant standards; liaise with the stakeholders for reporting and resources administration.