Representatives from 30 countries, including Great Britain and India, arrived in Tehran to take part in the exhibition, the Iranian Oil Ministry's Petroenergy Information Network reports.
"The exhibition as a desirable opportunity depicts a clear picture of cooperation among the countries," said Iranian Oil Minister Massoud Mir Kazemi.
Kazemi noted that the development goals for the Iranian energy sector rely on domestic capabilities while considering expanded ties with the international community.
He said the government aims to invest more than $200 billion in the oil and gas sector through 2015, reflecting the national determination to succeed. The presence of "hundreds" of energy companies at the exhibition shows nations opposing Iran are, in fact, sanctioning themselves, the minister added.
Western nations are pressing for tough economic sanctions on Iran as punishment for a controversial nuclear program. International oil and gas trader Vitol and Russian explorer Lukoil suspended business with Iran in part because of the pressure.
The Petroenergy report said attendance at the exhibition is up 10 percent from the previous year. The exhibition runs through Monday.