Northwest Airlines has asked a US bankruptcy court for an extension of about six months to file a reorganization plan, according to court documents filed on Friday.

Northwest asked a judge to extend until July 13 the time it has to exclusively file a plan and push back a deadline to September 12 for soliciting acceptances for the plan.

Competing plans cannot be filed during the exclusive period, which is currently scheduled to expire on January 12.

The airline, which filed for Chapter 11 bankruptcy protection in September, said it needs the extra time to reduce costs, restructure operations and restore its financial credibility. It is looking for total annual savings of USD$2.5 billion before it emerges from bankruptcy.

"This will take time and cannot be rushed," it said in the court filing.

Last month Delta Air Lines, which filed for bankruptcy the same day as Northwest, also asked a judge for about six more months to file its reorganization plan.