Canada's largest energy company on Wednesday posted operating earnings of $934 million or 62 cents per share, missing the average analyst estimate by a penny, according to Thomson Reuters.
A year earlier, Suncor (TSX:SU) posted operating earnings of $1.25 billion, or 80 cents per share.
Oilsands operations and refineries were taken down for planned maintenance work during the quarter. Production was further constrained when June flooding in Alberta caused pipeline outages.
"Following these events, production at our oilsands operations has been restored, and we are currently seeing strong performance," said CEO Steve Williams.
Net earnings, which include unusual or one-time items, were $680 million, or 45 cents per share, compared to net earnings of $324 million, or 21 cents per share.
A year earlier, Suncor took a $694-million writedown on a Syrian natural gas project. The company pulled its employees out of the Middle Eastern country when civil war broke out.
Total production was 500,100 barrels per day during the second quarter, down from 542,400 a year earlier.
In the oilsands, output averaged 276,600 barrels per day, compared to 309,200 barrels per day.
Third-party outages reduced production by about 36,000 barrels per day.
Earlier this year, Suncor said it was scrapping its Voyageur oilsands upgrader because of shifting market conditions.
Burgeoning production of light oil from regions such as North Dakota means it no longer makes economic sense to invest billions into a facility to convert heavy oilsands crude into a lighter product refineries can handle.
Suncor took a $1.49-billion writedown on Voyageur in the fourth quarter of 2012 and another $127 million in the first quarter of 2013.
The Voyageur upgrader was part of a $1.75-billion partnership inked between Suncor and French energy giant Total S.A. in late 2010.
A decision on whether to go ahead with the companies' jointly-owned Fort Hills mine is expected during the fourth quarter, while it's not known when the fate of their Joslyn oilsands mine will be decided.
Suncor's board also approved a quarterly dividend Wednesday of 20 cents per common share, payable Sept. 25.
Suncor is Canada's biggest energy company with a dominant position in Alberta's oilsands. In addition to huge mining operations north of Fort McMurray, Alta., it has steam-driven projects at Firebag and MacKay River.
In addition, Suncor has refineries in Edmonton, Montreal, Sarnia, Ont., and Commerce City, Colo. Those assets help shield Suncor from swings in commodity prices, as they translate into lower costs in that part of the business.