LONDON (AP) — British Airways on Friday reported its biggest full-year loss since the former national airline was privatised in 1987, mainly due to soaring fuel costs and weaker demand in recent months.

The company lost £375 million ($595 million) in the year ending March 31, compared with a profit of £712 million in the previous year. That is its worst result in more than two decades of business, the previous low point being a £200 million loss in 2001-2002.

British Airways consequently said it would not pay any dividends to shareholders or bonuses to managers for the year, and it invited employees to volunteer for unpaid leave or part-time working.

"The prolonged nature of the global downturn makes this the harshest trading environment we have ever faced and, with no immediate improvement visible, market conditions remain challenging," said Willie Walsh, the airline's chief executive.

The company said Walsh was giving up his salary in July, some £61,250 ($97,000) , and chief financial officer Keith Williams would forgo his pay of £36,667 ($58,000) for the month.

"Personally, I do not want extra leave or to work part-time. But I certainly want to make a contribution in recognition of the extremely challenging position we face," Walsh said. "This is no stunt. I do not easily give up anything I have earned."

Revenue rose 2.9 percent to £8.99 billion during the fiscal year, but fuel costs jumped 45 percent to £2.97 billion.

In its fourth quarter, British Airways said revenue slumped by 8.4 percent to £1.9 billion, resulting in an operating loss of £309 million. Full figures for the quarter were not disclosed.

The company offered no guidance for the half year or full year "because of the difficulty in forecasting revenues."

BA shares closed down 3.75 percent at 156.7 pence on the London Stock Exchange on Friday. The market was closed yesterday for the spring bank holiday.

"Levels of traffic volume and yields have not improved over the last quarter and any recovery may take longer than expected," said James Cooke, analyst at Panmure Gordon & Co. He rated the shares as "hold".

"The industry as a whole is facing extremely difficult times, but for some BA is seen as being as well positioned as it can be in the circumstances. With this in mind, the market consensus is a very cautious buy," said Richard Hunter, analyst at Hargreaves Lansdown Stockbrokers.

There was "no question" that staffing numbers would be cut, Walsh said, but gave no details.

"There are no base pay increases planned, and we are offering staff the option of unpaid leave and temporary or permanent part-time working," Walsh said.

"We are also in talks with our trade unions about pay and productivity changes."

Jim McAuslan, general secretary of Balpa, the pilots' union, said it would work with the company on cost-cutting.

"In particular, we will be seeking to avoid any compulsory measures and ensure that changes agreed by our members are recognised as an investment by them in the company's future," McAuslan said.

The airline booked a charge of £78 million for paying staff who were laid off during the year.

Walsh said BA was switching focus from premium traffic, which has fallen by 13 percent, to competing for lower-fare volume business.

"Significant pricing actions were required to stimulate non-premium traffic volumes, which were broadly unchanged year on year," the airline said.