SYDNEY (AFP) - Struggling Australian carrier Qantas on Tuesday said it was committed to slashing costs by A$2 billion (S$2.3 billion) but refused to confirm or deny a report that it will axe 5,000 jobs.

The airline has been battling record fuel costs and fierce competition from subsidised rivals and in December said 1,000 jobs would go while warning it faced a half-year loss of up to A$300 million.

The interim result is due on Thursday and the Sydney Daily Telegraph, citing a Qantas source, said the job losses would be much worse as the airline restructures its finances to convince the government it deserves a debt guarantee.

As well as sacking 5,000 staff, the newspaper said Qantas may sell some of its terminals.

The airline refused to go into details.

"There is fresh speculation about what things we will or won't announce on Thursday as part of our half-year results. We are not in a position to comment on that speculation," the flag carrier in a statement.

"We have said that we will be making some tough decisions in order to achieve $2 billion in cost savings over the next three years, which is a consequence of an unprecedented set of market conditions now facing Qantas."

Qantas has said it was facing "immense" challenges and has been lobbying the government to ease limits in foreign investment or provide state intervention to help shore up its bottom line.

Canberra has made clear there will be no taxpayer handouts but has flagged support for a relaxation of the Qantas Sale Act, which limits foreign ownership in the airline to 49 per cent, or a possible debt facility.

Qantas chief Alan Joyce argues that the cap is hurting Qantas's ability to compete by restricting access to capital, particularly against domestic rival Virgin Australia, which is majority-owned by state-backed Singapore Airlines, Air New Zealand and Etihad.

Following its profit warning in December, Moody's and S&P both downgraded Qantas' credit rating to "junk" status, increasing the cost of financing for the carrier and restricting access for investors that do not put their money in lower-rated companies.

The carrier pledged to press ahead with cost cutting regardless of whether the government decides to help.

"We've said that we must take steps to reduce our costs regardless of whether the federal government acts on the uneven playing field in the Australian aviation market," said the statement.

Qantas shares were trading flat on Tuesday morning at A$1.24.