Saleh Hendi underlined the wide reception of NIOC’s exploration blocks, adding, “The ROI of the fields is very attractive.”

Speaking on the sidelines of the Iran Oil and Gas Show on Monday, the official said foreign firms had so far invested $1.2 billion in exploration projects in Iran, adding given the country’s exploration potentialities, dozens of billions of dollars needed to be invested in the sector.

Iran is planning to hold licensing round for 14 exploration blocks in July.

"Of the 14 exploration blocks, 6 blocks are expected to be attractive to foreign investors and for which development agreements would be signed," Hendi added.

He said that Austria's OMV, Russia's Lukoil and China's CNPC had shown interest in the exploration blocks which were unveiled earlier in the day.

Hendi said seven blocks were located in the Zagros and Persian Gulf areas, including four commercial blocks.

The blocks cover more than 80,000 square kilometers and are located in six sedimentary areas in Iran.