A founding member of the OPEC cartel, crude oil sales make up 90 percent of Iraq's budget revenues. Before the outbreak of war on February 28, Iraq mainly shipped its oil -- roughly 3.5 million barrels per day -- from the southern Basra fields via the Strait of Hormuz.

The state-owned North Oil Company said it "has begun operating the Sarlo pumping station to resume pumping and exporting Kirkuk oil to the port of Ceyhan with an initial capacity of 250,000 barrels per day".

Iraq resumed oil exports from its fields in the northern Kirkuk province "after a disruptive period that posed a significant challenge to the oil sector," and in agreement with the autonomous Kurdistan Region, through which the pipeline to Turkey's port of Ceyhan runs.

Iraq has been scrambling to find a solution to export its oil, and there have been long-running talks with Iraqi Kurdistan to ship it through the autonomous region.

Kurdish authorities had asked for several measures in return, before agreeing to let the oil flow through the region's pipeline.

The Kurdistan natural resources ministry said that the Sarlo oil station began operating at 6:30 am (0330 GMT) to enable exports via the Kurdistan region pipeline to the port of Ceyhan.

Iran has closed the strait, through which as much as a fifth of the world's global crude oil and liquefied natural gas is normally shipped, to vessels from most countries.

Iraq's Oil Minister Hayan Abdel Ghani said his country was in contact with Iran to try to arrange passage for some of its oil tankers through the waterway.