ExxonMobil has reduced its stake in the 9.1 billion barrel West Qurna 1 field from 60 percent to 25 percent – but will still be the operator – following a signing ceremony in Baghdad on Thursday.The move is part of ExxonMobil’s plan to de-risk its Iraq assets.”The final process … has been completed and the agreement has been signed,” said Assem Jihad, the Oil Ministry spokesperson.PetroChina, the China National Petroleum Corp. (CNPC) subsidiary, now has 25 percent. Indonesia’s …