Of the nine train units ordered, seven will be delivered by the end December 2016.
ÖBB already operates 51 Railjets across Austria, Germany, Hungary and Switzerland.
Siemens Rail Systems CEO Jochen Eickholt said: "Our Railjet is the hallmark of more than 160 years of Siemens’ experience in the passenger coach industry.
"Our Vienna plant is home to the Siemens’ World Competence Center for the development and manufacture of passenger vehicles, so we are especially delighted that ÖBB have once again placed their trust in us and expanded their Railjet fleet to no less than 420 cars."
Designed based on Viaggio Comfort-type intercity vehicles, the Railjet trains are compliant with the international high-speed rail operation requirements.
Siemens’ Railjet trains are equipped with the Ecojet package comprising LED lighting and an energy-optimised air-conditioning system that uses CO2 sensors to detect the number of passengers in the carriage and adjusts its output accordingly.
The 186m-long Railjet trains are propelled in push-pull mode by a Taurus locomotive and can travel at a speeds of up to 230kmph.
ÖBB CEO Christian Kern said: "Quality is a decisive factor for us and our customers who will benefit immensely from the modernisation of our train fleet with another nine railjets."
Image: Railjet trains are propelled in push-pull mode and can travel at a speeds of up to 230kmph. Photo: courtesy of Siemens.