One of world's largest oilfields

* Experts expect slow start amid political uncertainty

(Adds details, background)

DOHA, Dec 7 (Reuters) - China National Petroleum Corp (CNPC) expects to begin work on Iraq's huge Rumaila oilfield imminently, the company's vice president said on Monday.

Work would start "very soon" on the field, Zhou Jiping told Reuters on the sidelines of a conference in Doha.

Last month, oil major British Petroleum Plc (BP.L) and China's CNPC signed a 20-year development contract for Rumaila, one of the world's biggest oilfields.

The contract, in which BP has said it would invest $15 billion, is Iraq's first major oil deal since the 2003 U.S. invasion.

Energy experts have said they expect BP and CNPC to be slow to pour funds into Rumaila, partly because of uncertainty over the outcome of Iraq's parliamentary elections in January.

Rumaila, with 17 billion barrels in estimated crude reserves, is the workhorse of Iraq's oil industry, producing almost half its total output of 2.5 million barrels per day.

The field's reserves alone are bigger than those of the whole of Algeria, a fellow member of the Organization of the Petroleum Exporting Countries (OPEC).

BP and its Chinese partner expect to increase Rumaila's output to 2.85 million barrels per day.

The field is located in the southern part of the country. (Reporting by Luke Pachymuthu; Writing by Raissa Kasolowsky; Editing by Inal Ersan and Anthony Barker)

CNPC to start Iraq Rumaila oil work very soon -  Source