Oman Rail Company (ORC) has extended the deadline for bids on the main deal for the first section of the national railway network from 21 December 2014 to 18 January 2015.

Contractors have asked for more time to prepare their proposals for a complex design on difficult terrain, according to local press.

The design-and-build package involves three sectors, which make up a 207-kilometre stretch from Sohar to Buraimi, of double-track, mixed freight and passenger non-electrified railway line. Each sector – spanning lengths ranging from 34-127km – includes tunnels and viaducts, as well as associated buildings.

ORC prequalified 18 consortiums to bid for the contract.

In 2013, Italian state railway group Italferr won a €28m ($37.3m) deal for the consultancy services for the preliminary design of the national railway.

Oman’s overall rail network involves the construction of a 2,244km-long network that will ultimately connect the sultanate’s major ports and cities, including Muscat, Sohar, Duqm and Salalah, in addition to linking with the UAE’s rail network. It is part of a wider investment in transport.

The first segment is due to start operating in 2018.