* Q2 EPS C$0.25 vs C$1.28
* Oil output down 9 pct, natural gas down 8 pct
* Shares fall 31 Canadian cents to C$42.25 (Adds details)
CALGARY, Alberta, July 30 (Reuters) - Second-quarter profit at Imperial Oil Ltd (IMO.TO), Canada's biggest oil producer and refiner, tumbled 81 percent on lower oil and gas prices, maintenance outages and weak refining results, the company said on Thursday.
Imperial, 69.6 percent owned by U.S. major Exxon Mobil Corp (XOM.N), said net income fell to C$209 million ($194 million), or 25 Canadian cents a share, from year-earlier C$1.15 billion, or C$1.28 a share.
Revenue sank 38 percent to C$5.3 billion.
Like other oil producers, Imperial's second-quarter earnings faltered as oil and natural gas prices sagged because of the recession and falling demand.
Benchmark oil prices averaged $59.79 a barrel in the period, down 52 percent from the year before, but up 38 percent from the first quarter. Natural gas was 67 percent lower than in the second quarter of 2008.
With the drop in profit, Imperial joins its majority owner, Exxon Mobil, where net income fell by two-thirds, lagging analyst estimates.
The companies are 50-50 partners in the C$8 billion Kearl oil sands project, where Imperial started major construction in the second quarter. They are also developing promising shale gas reserves in the Horn River region of British Columbia.
Imperial's oil production averaged 223,000 barrels per day, down 9 percent from 246,000 bpd in the year-earlier quarter. Natural gas production fell 8 percent to 286 million cubic feet per day from 310 million.
Syncrude Canada Ltd, the sprawling Alberta oil sands venture in which Imperial has a 25 percent stake, had a longer-than-planned coker unit shutdown in the quarter, restricting output.
Production from its wholly owned Cold Lake bitumen project was also held back by upkeep activity.
Imperial's refining and marketing division lost a net C$38 million in the quarter, after a year-earlier profit of C$239 million, on an increase in planned maintenance at two refineries and weak industry-wide margins.
Imperial company is about to be displaced as the top player in its part of the business when Suncor Energy Inc's (SU.TO) takeover of Petro-Canada PCA.TO closes on Saturday.
Imperial shares were off 31 Canadian cents at C$C$42.25 late in the session on the Toronto Stock Exchange.
$1=$1.08 Canadian Reporting by Jeffrey Jones; editing by Janet Guttsman