Iraq has named a new deputy oil minister, replacing an oil official who had been in the job since after the U.S.-led invasion in 2003, Iraqi oil officials in Baghdad said Tuesday.

In a ministry decree, Fayadh Hassan Niama was named to replace Ahmed al-Shammaa, because the latter had reached retirement age.

Mr. Shammaa was the deputy oil minister for downstream, and also used to oversee the Basra Gas Company project, a joint venture between Royal Dutch Shell PLC (RDSA), Mitsubishi and the state-run South Gas Company.

The decree also named Sameer Salman al-Taei as the new head of the state-run North Oil Co. that oversees oil fields in northern
Iraq . Mr. Taei, who used to be head of the oil fields department in the NOC, replaces Hamid al-Saedi, who has been director general since 2010.

The NOC is headquartered in the oil-hub city of
Kirkuk , which is at the center of a claim dispute between Iraq 's central government in Baghdad and the semi-autonomous Kurdish region in the north.

Kirkuk , some 250 kilometers north of Baghdad , is the heart of northern Iraq 's oil industry and has a mixed population of Arabs, Kurds, and Turkmen. North Oil Co.'s productive fields include the supergiant Kirkuk .

Iraq , which sits on the world's third-largest crude oil reserves, is looking to increase its oil production from around 3.3 million barrels a day to 3.7 million barrels a day by the end of 2013.