The third line of Tehran’s metro system is expected to be completed by 2015, according to Mohammed Montazeri, deputy managing director, planning and logistics at Tehran Urban and Suburban Railway Company.

Lines 1 and 2 of the metro scheme are already complete, with lines 6 and 7 under construction and due for completion in 2015 and 2016 respectively.

Montazeri says the main constraint to progress on the metro is financial issues.

Approximately 80 per cent of the metro equipment is produced locally and tendered to local companies.

Foreign companies are welcome to bid for work, if they can bring financing with them, says Montazari.

He adds that Iran’s new government and the thawing of the country’s foreign relations with Western powers could have a positive effect on the pace of the metro’s development.

The $19.8bn Tehran Metro is being built over multiple phases. It will have nine metro lines and four express lines, with final completion expected in 2025.