UPDATE 1-StatoilHydro starts 2-mth Mongstad refinery shutdown

(Adds details, background)

OSLO, Sept 2 (Reuters) - Norwegian oil and gas group StatoilHydro (STL.OL) began two months of scheduled maintenance work at its Mongstad refinery and oil terminal north of Bergen on the west coast on Tuesday, the company said.

The complete shutdown will last for 16 days, but partial closures will affect all parts of the refinery and quay facilities, StatoilHydro said.

Mongstad is Norway's largest refinery, with annual capacity of 10 million tonnes of crude oil and storage for more than a third of all crude produced by StatoilHydro on the Norwegian continental shelf.

The main products are petrol, diesel oil, jet fuel and other light petroleum products, and most of the output is exported to European markets.

A project is under way to build a gas-fired power and heating plant for the refinery with a start-up due in 2010.

"The goal is to make improvements which ensure stable and safe operations of the plant until the next scheduled shutdown in 2013, and prepare for the connection to the new combined power and heating plant," Mongstad manager Kjell Petter Aanes said in a statement.

Around 400,000 manhours of work will be performed during the 60-day scheduled shutdown, StatoilHydro said, adding that it would be the most extensive onshore maintenance ever carried out in Norway.

StatoilHydro owns 79 percent of Mongstad Refining and Shell (RDSa.L) 21 percent. (Reporting by John Acher; Editing by Kim Coghill)