The pilots' union at Northwest Airlines says the carrier is "risking labor peace" if it voids their collective bargaining agreement before another consensual deal is in place, according to court documents.

The Air Line Pilots Association asked a US Bankruptcy Court in a filing on Wednesday to defer the hearings on the airline's bid to void their contract and allow more time for the two sides to reach a deal.

Northwest plans to renew an earlier request that the judge let the carrier scrap the existing contract with its pilots and other union-represented workers if a deal is not reached by January 17. A hearing on the airline's motion is set for that day.

"Northwest is risking labor peace with its pilots," the union said in the document. "The unilateral implementation of Northwest's demands... would leave Northwest without a consensual pilot contract and the pilots with the right to strike."

Northwest, which filed for Chapter 11 bankruptcy protection in September, is seeking a total of about USD$611 million in annual savings from its pilots as part of a drive to achieve savings worth USD$2.5 billion annually.

The airline and the pilots reached an interim deal in November, in which the pilots agreed to yearly concessions amounting to USD$215 million.

Northwest, which has said that its labor costs are the highest in the industry, has been haggling with its pilots, flight attendants and ground workers over permanent savings.