Israel has imported as much as three-quarters of its oil from Iraq’s semi-autonomous Kurdish north in recent months, providing a vital source of funds to the cash-strapped region as it fights militants of the Islamic State of Iraq and the Levant (Isis). The sales are a sign of Iraqi Kurdistan’s growing assertiveness and the further fraying of ties between Erbil and Baghdad, which has long harboured fears that the Kurds’ ultimate objective is full-scale independence from Iraq. The imports highlight the significant inroads that oil from Iraqi Kurdistan is making into world markets, with Italy, France and Greece also emerging as big buyers. It is a trade conducted through secretive pre-pay deals brokered by some of the world’s largest oil trading companies, including Vitol and Trafigura. Israeli refineries and oil companies imported more than 19m barrels of Kurdish oil between the beginning of May and August 11, according to shipping data, trading sources and satellite tanker tracking. This would be worth almost $1bn based on international prices over the period.