Iraq has signed a final deal with U.S. and European oil giants Exxon Mobil Corp. and Royal Dutch Shell PLC to develop a major oil field in the south.

Under the 20-year deal, the consortium will develop the 8.6 billion barrel West Qurna Stage 1 field for $1.9 for every barrel produced. The deal could be extended for another five years.

The deal was signed Monday in Baghdad.

The field was among five oil and two gas fields left over from Iraq's first postwar bidding round held in June. The consortium initially asked for $4 per barrel produced, but later accepted Iraq's lower offer.

Last week, Iraq signed a deal with a consortium led by Italy's Eni SpA to develop another major oil field in the south.