Over 1800 Iranian and international companies from 32 states are scheduled to participate in the 19th International Oil, Gas, Refinery and Petrochemicals Exhibition which is to be held on May 6 in Tehran. Director of the Exhibition Akbar Nematollahi said that Iran is trying to change world atmosphere in its benefit by taking diplomatic methods. He went on to say that presence of foreign companies in this fair has been threefold. Referring to the unprecedented number of participants in the fair, he pointed out that the 19th exhibition hosts 600 foreign firms from 32 countries, while in the 18th fair the figure was only 195 companies from 15 states. Number of domestic companies is 1200, which was 850 during the 18th version of the event, he continued. The official said that the exhibition is a valuable opportunity for Iranian industrialists, who are eligible to have more share in the world, adding that strengthening ability for internal manufacturing through exchanging technical information with new industrial, scientific and research achievements are among main objectives of holding the fair. Iran ranks the third globally in terms of oil reserves while having the world's second-largest natural gas reserves after Russia with 34 trillion cubic meters of natural gas reserves.