The prospective bidders include:
• GEK Terna, Vinci, and Siemens
• J&P Avax, Ghella and Alstom
• Aktor and Hitachi Rail Italy, and
• FCC, Archirodon and Mytilineos.

A shortlist of potential contractors will be announced by the end of the year and construction is expected to begin in 2019.

Line 4 Section A will connect Alsos Veikou with Goudi serving 14 new stations, including interchanges with existing metro lines at Panepistimio/Akademia and Evangelismos.

Services will be operated by a new fleet of 18 750V dc trains and the line will be equipped with CBTC.