It could take three to five years for a new wave of Iranian oil to significantly increase world petroleum supplies and have a lasting impact on prices, the chief economist of the International Energy Agency said Monday. The prospect of a deal to lift Western sanctions in exchange for limits on Iran’s nuclear program has added a new layer of volatility to an oil market reeling from a historic collapse in prices, from about $115 a barrel last summer to a low of $47 in January. Brent crude, the global benchmark, was trading at about $59 Monday afternoon in London. Iranian officials have said they could ramp up production quickly, adding as much as a million barrels a day to the world’s supply. But Fatih Birol, the chief economist at the International Energy Agency, said in an interview that it would take time for Iran to boost its […]