Iraq's bid to auction off oil exploration rights Friday showed companies are still reluctant to enter the country.

Only two of the eight fields on offer resulted in deals in the first day of the country's second oil auction this year. Five in regions still plagued by unrest were withdrawn and a sixth field drew only one bid.

An Iraqi worker operates valves at the Rumaila oil refinery, near the city of Basra. Fears about security in some regions of Iraq produced mixed results in Friday's auction of oil reserves by the government. (Nabil al-Jourani/Associated Press Photo)

In all, 15 fields were to be offered in the two-day round, covering roughly a third of Iraq's 115 billion in proven reserves of crude. The deals are crucial for Iraq, which relies on oil for 90 per cent of its government budget. It needs help to boost production and repair its dilapidated oil infrastructure.

Security fears likely weighed heavily on executives of the 44 companies who took part. Earlier this week, a wave of attacks across Baghdad killed at least 127 people. The attacks shook confidence in the abilities of Iraq security forces as U.S. troops depart.

Two consortiums won rights to two fields with combined reserves of about 13 billion barrels in the relatively stable south. Shell and Malaysia's state-run Petronas beat out France's Total SA and China National Petroleum Corp. to win the southern Majnoon field in the Basra region. With 12.58 billion barrels, it was the biggest field on auction.

The Shell-Petronas pair will receive $1.39 per barrel produced, and said they would raise production from the current 45,900 barrels per day to 1.8 million barrels per day over a 10-year period.

The China National Petroleum Corp won a share of the second field, the 4.1-billion-barrel Halfaya field. It had joined with Petronas and Total, and outbid three other consortiums led by Italy's Eni, Norway's Statoil ASA and India's ONGC. The CNPC-Petronas-Total partnership will get $1.40 per barrel produced, and promised to raise production from the current 3,100 barrels per day to 535,000 barrels per day over 13 years.

Oil Minister Hussain al-Shahristani described the first day as a "great success," noting the per-barrel price that companies would receive was satisfactory for Iraq and the production targets they proposed were higher than those set by the government.

The companies must sign 20-year contracts and receive a flat fee per barrel produced.

With files from The Associated Press