Iranian oil exports may have reached a level on par with the average volume from before nuclear-related sanctions were enacted, a minister said Thursday.

Iran opened a domestic oil and gas exhibition in Tehran, bringing in domestic and international companies to review the opportunities. Iran this week signed a memorandum of understanding with Austrian energy company OMV and Roknoddin Javadi, the head of the National Iranian Oil Co. and deputy minister, said he met on the sidelines of the conference with representatives from British energy company BP and Royal Dutch Shell.

OMV said this week's agreement was the first step toward resuming formal operations in Iran, which was isolated by sanctions pressures for at least the last four years. Those sanctions started to ease in January in response to a multilateral nuclear agreement and Javadi said production and exports are on the rise.

According to the official Islamic Republic News Agency, Iranian crude oil exports for the Iranian month, which began April 20, are on pace to reach 2.1 million barrels of oil per day, a level IRNA reported as equal to pre-sanctions levels.

Iran said about 35 countries sent representatives to attend the three-day exhibition in Tehran. State-backed broadcaster Press TV reported there are U.S. companies represented at the event, though existing U.S. sanctions pressure on Iran makes it difficult to conduct financial transactions with Iran.

An Iranian conference in London in February was postponed indefinitely because Iranian delegates were having difficulty getting visas to attend the event.

Iran's efforts at a rebound come as crude oil prices remain far below levels two years ago despite a major rally in April. Some members of the Organization of Petroleum Exporting Countries, of which Iran is a member, mulled a production freeze to stabilize the market, though reservations from Tehran ruined the deal.

The NIOC director said Thursday exports and production would continue until Iran regains the market share lost to sanctions, adding any further consideration of a production freeze depended on oil sector strategies.