Iraq signed a contract Thursday with British energy giant BP aimed at more than doubling production from oil fields in the northern province of Kirkuk that were retaken from the Kurds last year.

The agreement was signed by Iraqi Oil Minister Jabbar al-Luaybi in Kirkuk, north of Baghdad, where the North Oil Company has its headquarters, AFP reporters said.

Iraqi forces reclaimed a string of major oil fields in Kirkuk after Iraqi Kurds in September voted for independence in a controversial referendum opposed by Baghdad.

The Kurds had taken over the fields in 2014 during the chaos of the Islamic State group's rampage across the country and exported oil to Turkey through their own pipeline.

Experts say work to renovate a parallel Iraqi pipeline could take up to two years.

Kirkuk province now has a production capacity of 420,000 barrels a day (bpd), according to Baghdad, but only 120,000 barrels a day are being pumped and exports from the region are at a halt.

The oil ministry said Thursday's deal aims "to increase production by 750,000 barrels per day".

Luaybi added that he would visit Turkey "soon, to study ways of reaching a deal on the pipeline from Kirkuk to the Turkish port of Ceyhan".

Iraq, the second largest producer in the OPEC cartel after Saudi Arabia, signed a consultancy contract with BP in 2013 to help the state-owned North Oil Company to develop the Havana and Baba Gurgur fields in Kirkuk province.

But it was never implemented as Baghdad lost control of the fields to Kurdish forces the following year.

Iraq reported its oil exports hit 109.6 million barrels a day in December, the same month that the government announced victory over IS.

Iraq in 2017 earned around $6.5 billion (5.3 billion euros) from crude sales, at $59.3 per barrel.