Delta Air Lines Inc. and Northwest Airlines Corp., the third and fourth largest airlines in the United States, filed for bankruptcy protection from creditors on Wednesday.

Delta Air Lines Inc., and Northwest Airlines Corp., hobbled by high fuel costs and heavy debt and pension obligations, became the third and fourth major carriers to enter Chapter 11 since the 2001 terrorist attacks after the United Airlines and the US Airways filed for bankruptcy protection in the past years.

Delta's total debt is roughly 28.3 billion dollars and it listed 21.6 billion dollars in assets, according to the filing by the company.

Atlanta-based Delta has lost nearly 10 billion dollars over the last four years despite announcing it would cut up to 24,000 jobs. Analysts said that Delta was expected to continue its normal schedule. However, as the company makes its way through bankruptcy court, some changes to Delta's operations could occur.

Northwest also faces 2.5 billion dollars in payments due to its underfunded pensions in the next couple of years, and has so far unsuccessfully pursued a change to federal law that would allow it to spread the payments over a longer term.

The company said in a news release it would continue to fly its normal schedule while reorganizing.

Like other airlines, Northwest has been hit by meteoric increases in jet fuel prices. But the fourth-largest airline also has the highest labor costs in the industry and has been losing money at the rate of 4 million dollars a day.

Source: Xinhua