A revised contract signed by British oil major BP and China’s CNPC for Iraq’s Rumaila oilfield has raised both companies’ stakes in a joint venture formed to develop the field, a senior Iraqi oil official said.

Under the revised contract, BP has cut the planned output target for the supergiant field to 2.1 million barrels per day (mbpd) from 2.85 mbpd and extended the life of the deal, BP and Iraqi officials said. The original contract had BP holding a 38 per cent stake in the Rumaila venture, while CNPC had a 37 per cent share and Iraq’s State Oil Marketing Organisation controlled the rest.

According to the revised deal signed, BP’s share rose to 47.6 per cent and CNPC’s to 46.4 per cent, while Iraq’s stake was reduced to 6 per cent, Thamer Ghadhban, top energy adviser to outgoing Prime Minister Nuri Al Maliki, told Reuters. He did not elaborate. BP and CNPC could not immediately be reached for comment.

After signing a series of service agreements with foreign companies in 2009-2010 to develop its giant southern oilfields, Iraq set an overall production capacity target of 12 mbpd by 2020, which would rival the output capacity of top oil exporter Saudi Arabia at 12.5 mbpd.

Foreign oil companies working in Iraq include BP, leader at Rumaila; ExxonMobil, in charge of West Qurna 1; Royal Dutch Shell, operator of Majnoon; and Lukoil, which is leading West Qurna 2 operations. But crumbling infrastructure, red tape and a lack of clear legislation have stunted investor interest. Baghdad has reduced its overall capacity target to 8.5-9 mbpd and returned to the negotiating table.