Global energy executives braved lingering violence and political uncertainty to attend the auction in Baghdad, the third bidding round since the 2003 US-led invasion, but Western companies either did not compete or failed to win.

In the previous two energy auctions last year, Iraq sold contracts to develop some of its biggest oilfields, setting the stage for its crude output capacity to quadruple to Saudi levels of 12 million barrels per day if everything goes to plan.

Wednesday's gas auction kicked off with South Korea's Kogas and Kazakhstan's KazMunaiGas Exploration & Production winning a deal to develop the largest of the three, Akkas gas field in the Sunni heartland of western Iraq.

Kuwait Energy and Turkey's TPAO won the bid for Siba gas field in Iraq's relatively peaceful southern oil hub of Basra, while TPAO, Kuwait Energy and Kogas won the third gas field, Mansuriyah, near the Iranian border in volatile Diyala province.

The only Western company to bid was French major Total. Analysts said Iraq's lack of gas infrastructure and security concerns kept other big global names away.

"There are a couple of uncertainties when it comes to Iraq such as the infrastructure, political situation and the situation of Iraq's gas industry in terms of technological innovation," said Cuneyt Kazokoglu, an analyst at JBC Energy.

"So because of these the interest is rather limited."

Major violence has abated from the peak of sectarian bloodshed three years ago, but foreign oil companies still face shaky security in a country struggling to tame a stubborn Islamist insurgency.

The winning bidders also have to build almost non-existing gas infrastructure and a pipeline network from scratch and brave the risks of operating in violent areas where some provincial opposition against the auction is already ramping up.

Iraq says the gas will be used to generate electricity domestically and as feedstock for industry, but some firms are also hoping to export to neighboring countries.

Thamir Al-Ghadhban, a top adviser to Prime Minister Nuri Al-Maliki, said on the sidelines of the auction that Iraq did not rule out exporting gas once domestic needs were satisfied.

"There is no doubt it was a very successful auction," he said. "I don't see a problem in the future with exporting gas."

TPAO vice president Besim Sisman said the group eyed exports from Siba either through Kuwait or the planned Nabucco natural gas pipeline to Europe.

"Nabucco is very important for us," he said.

On Mansuriyah, he said his company and its partners expected to invest $2.5 billion to develop it.

Iraq's economy is dominated by oil and its gas sector has long been neglected. But the government want to diversify the economy and broaden its source of revenues.

Thirteen companies registered for the auction including Italy's ENI, Edison, Norway's Statoil and Russia's TNK-BP, but not all registered firms bid on Wednesday.

The bidding round was delayed twice to give companies more time to study the contract terms.

The fields have estimated combined reserves of 11.23 trillion cubic feet of gas, about 10 percent of Iraq's total 112 tcf of proven natural gas reserves, the world's 10th largest.

Kogas and KazMunaiGas, who bid against a consortium of Total and TPAO, set a remuneration fee of $5.50 per barrel of oil equivalent at Akkas and proposed a plateau production target of 400 million standard cubic feet per day. The total investment will be about $4.4 billion, South Korea's Ministry of Knowledge Economy said in the statement.

Kuwait Energy and TPAO set a remuneration fee of $7.50 per barrel of oil equivalent for Siba and its plateau output target was 100 million cubic feet per day of gas. TPAO said the group  would invest $1 billion.

The partners planning to develop Mansuriyah accepted a fee of $7 per barrel of oil equivalent and set a plateau production target of 320 million cubic feet of gas per day. Investment in that field was expected to be $2.5 billion, TPAO said.