Japan Airlines Corp. careened deep into the red last business year and forecast another annual loss even as it slashes costs this year by half a billion dollars.

Asia's biggest carrier by sales said Tuesday it posted a group net loss of ¥63.2 billion for the 12 months through March, in stark contrast with last year's ¥16.9 billion profit.

International and business travel have slumped, hit first by volatile fuel prices and then by a slowing global economy.

The number of passengers on the airline's international routes fell 12.4 percent, while domestic routes carried 1.8 percent fewer people, JAL said.

"As demand for air transport weakened due to the effects of the global financial crisis, the JAL Group's core business of air transportation, and its other airline-related and travel-related businesses sustained sharp declines in earnings," the Tokyo-based carrier said in a statement.

It booked an operating loss of ¥50.9 billion on 12.5 percent lower revenue of ¥1.95 trillion despite a series of cost shaving measures, including annual bonus cuts and early retirement programs.

The months ahead don't look to be much better.

JAL forecast a ¥63 billion net loss on sales of ¥1.75 trillion for the year through next March, saying it expects even shaper declines in international passenger revenue.

The carrier aims to further reduce costs this year by ¥53 billion and ¥100 billion next business year by improving efficiencies in sales, maintenance and fuel usage. It said it is "positive that it will steer back into the black."