Iran increased its estimated oil reserves on Monday to a level which would return it to third place in the world after Iraq said last week it had overtaken its neighbour.   

Oil Minister Massoud Mirkazemi told a news conference Iran had 150.31 billion barrels of reserves, up from previous estimates which ranged from 132 to 138 billion barrels -- and he said that figure would be revised even higher soon.

'This latest figure will definitely go up by the end of the year,' he said.   

Last Monday Iraq raised its proven oil reserves figure by a quarter to 143 billion barrels, surpassing Iran and putting it behind only Saudi Arabia and Venezuela, according to BP data.   

Iran's upbeat estimate comes days ahead of an Opec meeting on Thursday where members of the oil producers club are likely to maintain their supply target.   

The Islamic Republic is under increasingly tough economic sanctions due to concerns about its nuclear programme, but it remains the world's fifth-largest oil exporter.   

It also sits on the world's second-largest natural gas reserves after Russia. Mirkazemi upped his estimate for Iran's gas reserves to 33.1 trillion cubic metres, from a previous estimate of 28 trillion cubic metres.   

Iran has discovered a new gas field in the southern Hormuzgan province, he said, with an estimated 70 billion cubic feet of gas in the field, 72 percent of which was recoverable.
 - Reuters