Oil and gas from Iraqi Kurdistan will soon be exported via pipelines through Turkey, after a tranch of contracts were signed in secret this week, Reuters news agency reports.
The deals were reportedly completed on Wednesday during a three-hour meeting between Nechirvan Barzani, prime minister of the Kurdistan Regional Government, and Recep Tayyip Erdogan, Turkish prime minister.
The agreement is likely to anger officials in Baghdad, who claim dominion over all of Iraq's oil resources.
An official told Reuters on Thursday that such an energy deal would be "an encroachment on the sovereignty of Iraq".
The state-backed Turkish Energy Company (TEC), which Turkey set up to operate in northern Iraq, has also signed a contract to operate in 13 exploration areas.
In about half of those, it is teaming up with ExxonMobil, the US oil company.
The contracts also envisage the building of a new oil pipeline and a gas pipeline, aimed to help the region's oil exports to climb to one million barrels per day by 2015.
The gas flow is likely to start by early 2017.