The Moroccan rail authority ONCF has called for companies to bid for the design work for bridges and viaducts on the train line between Casablanca and Marrakech.
The contract is in relation to the section of the track serving Casablancas Mohammed V airport.
The bid deadline is 30 October.
The tender is part of a wider programme to increase the capacity of the Tangier-Marrakech railway line. The wider project includes the construction of a 148-kilometre third track between Zenata and Kenitra, which will be dedicated to freight traffic.
It also covers the upgrade and partial double-tracking works on a 40km stretch of rail between Settat and Marrakech. The entire project is scheduled for completion in 2016.
Financing for the project was secured from the African Development Bank in December 2010. The bank lent the ONCF a five-year investment loan of 300m ($398m). Total project costs amounted to 438.2m, with the remainder of the funds to be raised by the rail authority.