Iraq's oil exports fell to 2.484 million barrels per day (bpd) in May from 2.62 million in April due to a slowdown in Kirkuk oil shipments after repeated pipeline attacks and maintenance operations in the south.
Iraq shipped 2.198 million bpd from the southern oil hub of Basra and 286,000 bpd from the northern fields around Kirkuk, including 15,000 barrels trucked to Jordan.
The May export figure is lower than the initial level of 2.6 million bpd given by oil minister Abdul Kareem Luaibi on May 26.
Experts say lower exports show the 2.9 million bpd set in the 2013 federal budget will be difficult to achieve.
Problems include repeated attacks on the northern pipeline, shipment stoppages from the Kurdish region and infrastructure bottlenecks in the south.
Iraq aims to double its oil output over the next three years and has a long-term goal of 12 million bpd. The OPEC member is likely to manage around half that amount, industry experts say, due to infrastructure and logistical hurdles.
Yet Iraq, which has the world's fourth-largest oil reserves, is still expected to be the world's biggest source of new oil supplies over the next few years.