The order is worth €550m and comprises three-car sets configured for suburban and regional services.

Thirty of the trains will be used on the Vienna S-Bahn network, replacing ageing class 4020 emus, and each set will have six sets of doors. The remaining 70 trains will have just 4 sets of doors and will be used on regional services, replacing locomotive-hauled push-pull sets. Lower Austria will receive 35 trains, while 18 will go to Styria and 17 to Upper Austria.

There has been a lot of discussion between ÖBB and Siemens on the amount of assembly work to be carried out by ÖBB. At first Siemens was unwilling to carry out assembly at ÖBB facilities and would only accept employment of ÖBB staff at Siemens sites. It has now been agreed that assembly will take place at ÖBB's Jedlersdorf works, whilst bogies will be supplied by the Siemens plant at Graz.

The ÖBB Desiro ML will have a maximum speed of 160 km/h and 100% low-floor with an entrance level of 600mm. The S-Bahn trains will have 244 seats, while the regional variant will seat 259.

The ministry of transport will provide 90% of the necessary finance, with the remainder coming from ÖBB via public service contracts with regional authorities. The contract will be signed after the formal closing period, and deliveries will begin at the end of 2015 at a rate of three sets per month.