Baghdad's decision will not affect oil exploration in autonomous Kurdistan, a spokesman for the state-run Korea National Oil Corp (KNOC) told AFP.

A South Korean consortium led by KNOC began exploring oilfields this year in Kurdistan. A deal was signed with the region's government in June last year despite protests from Iraq's central government.

Iraq said Thursday that its oil minister Hussein al-Shahristani had penalised South Korea's top refiner SK Energy and KNOC by banning them from taking part in tenders.

It said Korean firms could bid in the future if they cancel the 2.1-billion-dollar deal with Kurdistan.

SK Energy and KNOC said they have no plan to cancel the deal.

"That's an important deal. We cannot accept the minister's remarks that it is against Iraqi law," the KNOC spokesman said.

"However, we are also ready to take part in oil exploration projects controlled by Iraq's central government."

The spokesman said Iraq should respect a 3.55 billion dollar oil-for-development deal forged between the two countries in February during Iraqi President Jalal Talabani's visit to Seoul.

That deal would allow Seoul to develop oilfields in southern Iraq's Basra area. In return, South Korea would help build power plants and other infrastructure in the war-torn country.

The deal with Kurdistan granted the KNOC-led consortium access to eight oilfields believed to hold 7.2 billion barrels of untapped crude. Five of the fields are located near the capital Arbil.

Iraq has the world's third largest proven oil reserves with more than 115 billion barrels.

But the central and Kurdish regional governments have been at odds over sharing the nation's oil wealth.

South Korea imports almost all its oil and gas. It is seeking worldwide exploration deals and stakes in foreign energy firms to secure the nation's supplies.