(Reuters) - Imperial Oil Ltd (>> Imperial Oil Limited), Canada's No.2 integrated oil producer and refiner, reported a surprise quarterly loss due to the impact of wildfires in Fort McMurray, Alberta.

Imperial, in which Exxon Mobil Corp (>> Exxon Mobil Corporation) holds a 69.6 percent stake, said its gross production averaged 329,000 barrels of oil equivalent per day (boepd) in the second quarter, compared with 344,000 boepd a year ago.

The Alberta wildfires reduced output by about 60,000 barrels per day and net income by an estimated C$170 million, Imperial said on Friday.

Like many of its peers operating in northern Alberta's oil sands, Imperial was forced to shut down its Kearl project in May as a precaution against the wildfires.

However, Imperial's share of output from Kearl shot up nearly 20 percent to 110,000 barrels per day of bitumen in the second quarter.

Exxon Mobil's Canada unit has a 29 percent stake in Kearl.

Imperial sold bitumen from oil sands for an average price of C$29.45 per barrel, nearly C$20 per barrel lower than a year earlier.

Imperial is now ramping up Kearl to full capacity of 220,000 barrels per day.

The company reported a net loss of C$181 million ($138 million), or 21 Canadian cents per share, in the second quarter ended June 30, compared with a profit of C$120 million, or 14 Canadian cents per share, a year ago.

Excluding a gain on asset sales, the company's loss was 22 Canadian cents per share, compared with analysts' average estimate of a profit of 3 Canadian cents, according to Thomson Reuters I/B/E/S.

Total revenue and other income fell 14.4 percent to C$6.25 billion, beating the average analyst estimate of C$5.66 billion.

(Reporting by Swetha Gopinath and Nia Williams; Editing by Anil D'Silva, Saumyadeb Chakrabarty and Maju Samuel)

Stocks treated in this article : Exxon Mobil Corporation, Imperial Oil Limited