* Suncor oil sands output up 2.7 pct year over year
* Average output drops from April
* Upgrader maintenance cuts production
CALGARY, Alberta, June 3 (Reuters) - Suncor Energy Inc (SU.TO) said on Thursday that output from its oil sands operations rose last month, despite the shutdown of its largest upgrader for planned maintenance.
Suncor, Canada's largest oil and gas company, said that output from its oil sands operations averaged 304,000 barrels per day in May, up 2.7 percent from the same month last year.
However May production was down 8.7 percent from April's 333,000 bpd average output as the company began scheduled maintenance on its Upgrader 2 unit on May 17.
Work on the upgrader, which converts tar-like bitumen from the oil sands into refinery-ready synthetic crude, is expected to last six weeks.
Sneh Seetal, a spokeswoman for Suncor, said the maintenance shutdown is cutting output from the company's Fort McMurray, Alberta, operations by 85,000 barrels per day.
The company said its year-to-date oil sands output has averaged 250,000 bpd and it is targeting full-year average production of 280,000 bpd.
Suncor shares rose 12 Canadian cents to C$33.29 on Thursday on the Toronto Stock Exchange.
$1=$1.04 Canadian Reporting by Scott Haggett; editing by Rob Wilson