Kurdistan has begun to export crude oil directly to world oil markets through Turkey, industry sources said on Monday, which poses the biggest challenge yet to Baghdad's claim to full control over Iraqi oil.

The export of crude, in addition to small volumes of niche condensate, demonstrates the semi-autonomous region's growing frustration with Baghdad as it moves towards ever greater economic independence, the sources said.

The volume of oil involved is small, but industry sources said the direct export is highly symbolic as the KRG seeks more financial independence from Baghdad.

The first crude has been delivered by truck to the Turkish port of Mersin on the Mediterranean, shipping and industry sources said.

"The KRG gave us permission to start crude exports from the Taq Taq oilfield," Genel Energy President Mehmet Sepil said in an interview.

Now the Kurdish region is adding crude from the Taq Taq oilfield, where London-listed explorer Genel Energy has a stake, to its slate of exports.

A fresh cargo of condensate is also ready to sell through an imminent tender, said a shipping source.

Industry sources reckon around 15,000 barrels per day (bpd)of condensate from the Khor Mor gas field are reaching the Toros terminal in Turkey. Crude oil exports from Taq Taq, for now, are also small.

In exchange, Turkey is sending back refined products to the Kurdish region, which is short of fuel.