TEHERAN (AFP) - Russia plans to open a US$5 billion (S$7 billion) credit line for Iran to help finance infrastructure projects in the country, officials from both countries said Thursday during a visit by Moscow's energy minister, Alexander Novak.

"We hope we can open a US$5 billion credit line," Novak told Iranian Telecommunications Minister Mahmoud Vaezi, according to Isna news agency.

Transportation Minister Abbas Akhoundi said after meeting Novak that "the Russians are going to allocate a credit line for infrastructure projects in Iran."

"The first project would be electrifying the Garmsar-Incheh Borun train line (connecting north central Iran to the northeastern border with Turkmenistan) at a cost of US$1.2 billion financed through the credit line," state television quoted him as saying.

Novak was accompanied by representatives from 50 Russian companies "ready to invest in Iran", he told First Vice-President Eshaq Jahangiri, according to the official Irna news agency.

Bilateral trade stands at "more than US$1 billion", Novak said, which is "not enough" and has to be raised, asserting that Iran is Russia's "most important economic and trade partner".

The two countries discussed expanding trade in oil, gas, electricity, transport, and telecommunications as well as defence cooperation.

Novak's visit comes in the wake of a July agreement between Iran and major world powers, including Russia, to curb Teheran's nuclear programme.

Jahangiri said Iran hopes that "in the implementation of the nuclear agreement, Russia would also play as constructive role" as it had during the negotiations.

Under the deal, UN and bilateral sanctions on Iran will be lifted, effectively providing a hefty boost to the economy and opening up all sorts of trade and investment opportunities to outsiders.