Cenovus Energy Inc. posted a larger-than-expected $668-million net loss in the first quarter of 2015, after crude oil and gas prices plunged.

One of Canada's largest oilsands producers, Cenovus increased its oilsands output by 20 per cent from a year earlier to 144,000 barrels a day.

Conventional oil production decreased by four per cent, while natural gas production was down three per cent.

But its realized prices for oil fell 47 per cent to $37.66 per barrel and natural gas prices fell by 25 per cent to $4.47 per thousand cubic feet.

Cash flow declined by 45 per cent in the last year to $495 million for the quarter, the company said.

But Cenovus said it has decreased its production costs across the board and raised $1.4 billion on markets to increase its financial resilience.

At the same time, it laid off workers and cut capital spending projections to $1.8 to $2 billion this year, down 40 per cent from 2014.

The Calgary-based company had an $88-million operating loss in the first quarter, compared with a $378-million operating profit a year earlier.

Cenovus said Wednesday it expects to increase production by 100,000 barrels a day by 2016, despite continued low prices.

"I think there's continuing risk here in the second quarter, because the of the potential for storage congestion, that we might see even weaker prices," Brian Ferguson said in an interview.

In North America, oil is being stored in tanks in the hopes that it will sell at a better price down the road. There have been concerns that as those tanks fill up, prices could deteriorate.

"One of the things we're very closely monitoring is supply and we've seen clearly a big drop in the rig count," said Ferguson. "That has not translated to a drop in supply yet in the U.S. I think we'll have more information, a clearer view in the direction of oil prices perhaps in the third quarter."