An Austrian appeals court on Tuesday authorised the extradition to the United States of Ukrainian oligarch Dmytro Firtash on bribery charges, overturning an earlier ruling.

Firtash, 51, one of Ukraine's richest men and previously a supporter of ousted president Viktor Yanukovych, was arrested in Austria in March 2014. 

Last April a judge in Vienna had rejected the US request to extradite him on the basis that the demand was "politically motivated".