12/06/2012 10:23 EST | Updated 02/05/2013 05:12 EST

Unplanned maintenance crimps Suncor oilsands production; Firebag 4 starts up

CALGARY - Suncor Energy Inc. said unplanned maintenance work at its oilsands plant in November caused monthly production figures to come in lower than expected.

Output at the base plant averaged 312,000 barrels per day during November, but ended the month at a rate 380,000 barrels once the issues had been resolved.

Suncor (TSX:SU), Canada's largest energy company, expects to meet its annual oilsands production target of between 325,000 to 340,000 barrels per day, although it will be at the lower end of that range.

The Calgary-based company also announced Thursday that the fourth phase of its steam-driven Firebag project has produced first oil and finished off November producing about 130,000 barrels per day.

On Canada's East Coast, the Terra Nova offshore platform is in the process of starting up following some planned maintenance work. It is expected to return to full production rates at the end of the month.

Company-wide production for 2012 is expected to fall within its target range of 540,000 to 580,000 barrels per day.

Suncor shares were off 14 cents to $32.54 in mid-morning trading Thursday on the Toronto Stock Exchange.