Siemens has long been in negotiations with Iran over an order for track technology and ICE 3 trains, a model of intercity train in use in Germany. The deal would be worth more than 2 billion euros ($2.25 billion), industry sources say.

German Economy Minister Sigmar Gabriel traveled to Iran at the start of the month and during that trip Siemens got an order to build parts for 50 locomotives.

Germany has traditionally had close economic ties with Iran, and after last year's nuclear accord, which paved the way for ending sanctions in place for years, German firms are now seeking business there again.

(Reporting by Markus Wacket; Writing by Michelle Martin; editing by John Stonestreet)