The Times daily said Guardian staff were expecting 100 jobs to be cut, although The Daily Telegraph said any layoffs would be announced in March.
Executives from Guardian News and Media, the newspaper's publishers, told staff at a meeting on Monday that the group would be cutting around 54 million pounds in costs.
Operating losses in the year to March 2015 were expected to be 53 million pounds, the executives said, adding that the aim was to break even in three years.
"Growing the cost base more than revenue is simply not sustainable," chief executive David Pemsel was quoted as saying at the meeting.
Also Read
Pemsel said that the newspaper could even consider moving out of its offices near King's Cross station in London although nothing had been decided.
"Are we moving from King's Cross? Nope. Are we looking at everything? Yes," he said.
The executives declined to comment on potential cuts to The Guardian's 1,960 staff. The Telegraph said that job losses were due to be revealed in March.