Suncor Energy, Canada's biggest oilsands player, has posted a net loss of $2 billion for the final three months of 2015 as it was walloped by the steep drop in crude prices.

In addition to the oil price collapse, Suncor's bottom line was dragged down by nearly $1.6 billion in impairment charges and a $382 million foreign exchange loss related to its U.S. dollar-denominated debt.

A year earlier, it posted a net profit of $84 million.

Stripped of unusual items, Suncor's operating loss amounted to $26 million, compared with profits of $386 million a year earlier.

Company-wide output grew to 582,900 barrels of oil equivalent a day during the fourth-quarter from 557,600 barrels during the prior year.

Suncor has ratcheted down its spending plans for 2016, with a capital budget of between $6 billion and $6.5 billion compared with the $6.7 billion to $7.3 billion range it set in November.

'Significantly overachieved' on layoffs

CEO Steve Williams says Suncor originally had a goal of chopping 1,000 employees in 2015 — both full time employees and contract workers.

But he says they "significantly overachieved that goal, taking just over 1,900 people out," but up to 250 employees were transferred to growth projects.

"So the net reduction in 2015 was about 1,700 people. So we almost doubled what we set as an objective at the beginning. And that's an indication it wasn't about a numbers target it was about really working on our underlying business processes to become more productive." said Williams.

The CEO says Suncor is now towards the end of those reductions.

The company is assuming a U.S. benchmark crude price of US$39 a barrel for 2016.

Canadian Oil Sands deal

In October, Suncor launched a hostile bid for Canadian Oil Sands, whose sole asset is a 37-per cent stake in the Syncrude oilsands mine. 

Suncor has a 12 per cent interest and has said it can improve operations at the glitch-prone mine if it has a larger share of it.

After months of waging a bitter takeover battle, the two sides came to an agreement in January.

Suncor bumped up its offer to 0.28 of one of its own shares for each COS share, versus 0.25 previously. Shareholders have until Friday to accept the deal.

"We are pleased that the board of COS is supporting our offer," said Williams. "We believe that, working with the operator, we can drive real improvements in Syncrude's performance with a larger ownership interest, creating value for our shareholders."

With files from CBC News