BAGHDAD, June 30 (AFP): British energy giant BP and China's CNPC International Ltd were unveiled Tuesday as the first foreign firms in decades to win contracts to invest and develop in Iraq's war-battered energy sector.

The companies succeeded in their bid for the giant Rumaila oil field in southern Iraq, which has known reserves of US$17.7 billion barrels, the oil ministry announced.

The contract was the first to be awarded in open tendering for six major oil fields and two gas fields, nearly four decades after Saddam Hussein's party nationalised the Iraqi energy sector.

"The companies accepted to be paid two dollars per barrel," said Oil Minister Hussein al-Shahristani.

Under the terms of the 20-year contract, BP and CNPC have six years to increase production at Rumaila to 2.85 million barrels per day.

However, several foreign companies rejected the terms laid down by the government and withdrew their offers for other smaller oil fields as well as a gas field.