Ministry spokesman Assem Jihad said on Wednesday that the companies will vie for developing the 4.4-billion-barrel Nasiriyah field and the construction of a 300,000 barrel a day refinery nearby. Jihad added that the actual date for receiving bids has not been set yet.
The companies are Russia's Zarubezhneft and Lukoil, China's CNPCI, U.S.Brown Energy, India's Reliance Industries, Franc's Total and Japan's JGC & Tonen General.
The field is located in Thi Qar province, about 320 kilometers (200 miles) south of Baghdad. Iraq sits atop of 143.1 billion barrels of proven oil reserves. Oil exports make up nearly 95 percent of Iraq's budget.