Iran is seeking $2.5 billion investment to modernize its oil tankers fleet following the lifting of sanctions against Tehran, managing director of National Iranian Tanker Company (NITC) was quoted as saying by state news agency IRNA.

Iran emerged from years of economic isolation after crippling sanctions were lifted in January in return for Tehran complying with steps to curb its nuclear ambitions.

Reuters reported last month that two Chinese firms were pushing for multi-billion dollar deals with Iran to modernize its shipping fleet and build a high-speed railway.

"To expand Iran's oil tanker activities, $2.5 billion will be invested in it," said Ali Akbar Safaei, managing director of National Iranian Tanker Company (NITC).

NITC has around 70 tankers but many of them are aging and require valid insurance, testing, inspection and certification, known as ship classification, to be able to ply international waters again.

Safaei said that NITC was the first Iranian company that has managed to rent its ships to foreigners after the lifting of sanctions.