The Calgary-based company says net income was $221 million, down from $232 million a year earlier.
On a per share basis, the earnings amounted to 46 cents, down from 48 cents per share a year earlier and missing the average analyst estimate of 50 cents per share, according to Thomson Reuters.
Cash flow from operations was $418 million, or 86 cents per share, compared to $363 million, or 75 cents per share, a year earlier.
The Syncrude mine, north of Fort McMurray, Alta., produced an average of 298,000 barrels per day, up from 252,300 barrels per day a year earlier.
But the price Syncrude's oil gets was 14 per cent lower than a year ago at $89.99 per barrel during the quarter.
It's not unusual for heavy oilsands crude to get a lower price than West Texas Intermediate, a key U.S. light oil benchmark, because it's harder to process and further away from market. However, lately that price gap has been painfully steep at around US$40, causing a lot of pain for oilsands producers.
WTI itself traded at an average discount of US$18 in 2012 to global varieties, meaning Canadian producers have been facing a double whammy.
Canadian Oil Sands CEO Marcel Coutu said Syncrude was in better shape than other Western Canadian heavy oil producers because its bitumen is upgraded into a premium product called synthetic crude oil.
"Producers in western Canada generally experienced a further discount to WTI oil prices; however, pricing for our high-quality SCO blend averaged a discount of only $2.50 per barrel relative to WTI, demonstrating the value of our upgrader," he said in a release.
"We expect the differential between WTI and global crude oil prices to narrow as additional pipeline capacity comes on through 2013 and 2014. Our unhedged approach allows us to capture any upside in WTI oil prices."
For 2013, production at Syncrude is expected to range from 105 million to 115 million barrels, taking into account some planned maintenance work later this year.
Canadian Oil Sands owns a 37 per cent stake in the Syncrude mine, the biggest such project of its kind in the world.
Syncrude's other owners include Imperial Oil Ltd. (TSX:IMO), Nexen Inc. (TSX:NXY), Suncor Energy Inc. (TSX:SU), China's Sinopec, Mocal Energy Ltd. and Murphy Oil Co. Ltd.
Nexen has agreed to be bought by China National Offshore Oil Co. for $15 billion, though the deal has yet to close. Once it does, Chinese state-owned interests will own 16 per cent of Syncrude.
Canadian Oil Sands also said Thursday it is keeping its quarterly dividend steady at 35 cents per share.
Canadian Oil Sands shares were off 2.7 per cent to $20.99 on the Toronto Stock Exchange Thursday. It reported its results after markets closed.