Iran [1]'s oil exports have fallen by an estimated 40 percent since the start of the year as Western sanctions tear into the country's vital oil industry, the International Energy Agency said on Wednesday.

The agency, which represents the interests of major consuming nations, said preliminary indications suggested exports - the lifeblood of Iran's economy - fell to 1.5 million barrels per day in April-May from 2.5 million at end 2011.