Suncor Energy said it expects a fire-damaged oil sands upgrader to be out of service until early April, forcing Canada’s biggest energy company to cut its production targets for the year.

Suncor said the extended repairs on its 125,000 barrel per day (bpd) U1 upgrader, damaged in a February 9 fire, will force it to lower its 2010 oil sands production forecast of 300,000 bpd issued less than three weeks ago.

While it makes repairs to the upgrader Suncor expects to produce just 210,000 barrels of bitumen and synthetic crude per day this month, and 230,000 bpd in March.

The company will release a revised production forecast for its massive oil sands operations near Fort McMurray when it releases its first-quarter earnings on May 4, but analysts are already lowering their profit expectations because of the cut in output.

“In response to the announcement, we have revised our (first-quarter) oil sands production volumes to 198,000 bpd (previously 298,000 bpd),” Andrew Potter, an analyst with UBS Securities, wrote in a note to clients. “As a result of these revisions, our 2010 operating earnings has been brought down to C$2.08 per share”