TEHRAN: Iran boasted Monday its proven oil reserves have risen by nine percent to 150.31 billion barrels, a week after neighboring Iraq claimed it had overtaken Tehran in terms of size of crude reserves. The increased assessment was partly due to new discoveries, Oil Minister Masoud Mirkazemi told a news conference, adding that the figure “will definitely go up” by the end of the Iranian year in March 2011. “Our oil reserves are today at 150.31 billion barrels,” Mirkazemi said, compared with a previous figure of 138.0 billion barrels. “Our calculations are still ongoing. This figure is from a six month report based on production information and new discoveries,” he added. On Oct. 4, Iraq reported a sharp rise in proven oil reserves that it said had catapulted it into third place worldwide, behind Saudi Arabia and Venezuela. It announced a new figure of 143.1 billion barrels of oil, representing a 24 percent increase over the previous level of 115 billion barrels. Iran is the second largest member of the Organization of Petroleum Exporting Countries (OPEC), behind Saudi Arabia. It also has the world's second largest natural gas reserves after Russia. Mirkazemi said Iran has discovered a new gas field, named Sefid with “70 billion cubic meters of gas, 72 percent of which can be exploited,” in Hormozgan province on the Gulf. He added that Iran's gas reserves now stand at 33.1 trillion cubic meters. Iran is under mounting international pressure over its controversial nuclear program and Western firms have either pulled out or delayed their commitments in the vital energy sector after new sanctions were imposed on Tehran. Under threat of US sanctions, European oil firms Total, Shell, Statoil and Eni have pledged to stop investing in Iran, a US official said last month. Japanese oil developer Inpex Corp. also plans to completely withdraw from Iran's largest onshore oil field project to avoid possible US sanctions, reports said. – Agence France