Iran has launched feasibility studies for a cross-border rail network to link two of its Gulf ports to the southern Iraqi city of Basra.

The first phase of the proposed line would run for 30 kilometres from Basra across the border to the Iranian port of Khorramshahr, then a further 80 kilometres to the larger Imam Khomeini port.

The study has been undertaken by the Iranian group Metra Consulting Engineers, with approval from Baghdad.

Iraq has been keen to develop new trade outlets from its second-biggest city, and cultural and business links with Iran are particularly strong in the south of the country.

From Basra, trains running from the Iranian coast would be able to travel on to Baghdad on the recently reopened line between the two cities.

"The Iraqi government has been asking about a rail link to our [Iran's] Gulf ports for some time," says an official from Metra. "We do not have an estimated cost for the project yet but it should not be too expensive and it opens up trade routes along the coast and in the southwest of the country.

"There are a lot of opportunities from linking the ports to Basra. It has not yet been decided who will pay for the line, but I think it will be the Iranian government."

The direct link between Imam Khomeini and Khorramshahr had been under consideration for some time by Tehran.

Currently, the railway between the two makes a 100-kilometre detour inland to the city of Ahvaz before running back to the coast.

"For trade between the two sites, it makes sense to link the ports directly, and from Khorramshahr it is a very short distance to Basra," says the Metra official.

Metra's feasibility study will consider the technicalities of checking and making the land safe along the Iran-Iraq border, which was heavily mined during the war between the two countries in the 1980s.

"We will have to check the mine field," says the Metra official. "It has been 99 per cent cleared, but only 99 per cent."