Iran has claimed that rising of its oil exports has no negative impact on the markets. Iranian oil minister Bijan Zanganeh, before leaving for an OPEC meeting in Vienna today said, markets have absorbed its doubling of oil exports following the lifting of international sanctions. Iranian oil production has reached nearly four million barrels per day, around the same level as before sanctions were imposed.OPEC, which pumps around a third of the world's oil, has historically responded to a fall in prices by cutting production, but this time it has maintained output as it seeks to fend off competition from US shale producers.