UPDATE 1-Fire hinders Suncor oil sands processing unit

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TORONTO, Dec 1 (Reuters) - Suncor Energy Inc (SU.TO) said on Monday its oil sands operation will run at reduced rates in December as it repairs a key processing unit at the sprawling northern Alberta facility that caught fire last week.

Suncor said it would produce about 235,000 barrels of synthetic crude a day this month, but stressed the unscheduled work on its upgrader would not affect its targeted output of 300,000 barrels a day in 2009.

The company said the Nov. 26 fire to the upgrader -- one of two -- was minor and extinguished quickly without injuries. Repairs are expected to take three to four weeks and in that time the unit will operate at reduced rates.

The fire ignited during the start-up of a vacuum unit following the completion of scheduled maintenance, Suncor said.

Suncor's oil sands operations -- the country's second largest after the Syncrude Canada Ltd joint venture -- had suffered mechanical problems in the summer and autumn when a hydrotreater unit was shut for unplanned repairs. (Reporting by Jeffrey Jones; Editing by Christian Wiessner)