Some 600 major energy companies from 32 countries are taking part in the annual event, which opened on Tuesday and is to run till May 9, Iran Daily newspaper reported.
About 1,200 domestic energy companies are also participating in the high-profile oil show.
Energy firms from Russia, China, the United States, Canada, France, Germany, Japan, South Korea, Italy, Australia, Italy, India, Turkey and the UAE are displaying their capabilities during the four-day exhibition.
The participation of foreign companies has nearly tripled despite the US-led sanctions on Iran’s energy sector.
Last year’s event featured 195 companies from 15 countries.
On the sidelines of the exhibition, Amir Abbas Hosseini, the Research Institute of Petroleum Industry’s deputy for international and technology affairs, told reporters a German company will help Iran develop its domestic technology on producing fuel from heavy oil.
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