ATLANTA — Delta Air Lines Inc. said yesterday that if its pilots strike it would be "murder-suicide" and in effect put the nation's third-largest carrier out of business.

The comments by the Atlanta-based airline in a court filing came two days before a U.S. Bankruptcy Court judge in New York will hold a hearing to discuss Delta's request to reject its pilots' collective bargaining agreement.

Delta said in the filing that if its motion is granted it will impose $325 million in concessions it is seeking from its pilots.

The Air Line Pilots Association, which represents Delta's 6,000 pilots, has raised the prospect of a strike if the contract is rejected by the court, and it has scheduled a rally for today to defend the contract.

Delta said a strike would be disastrous and, it maintains, illegal.

Union spokesman John Culp said the pilots are united in their position, though he stressed there has been no determination on a specific course of action.

"No airline in the modern era has resorted to contract rejection to get what they want and we will not willingly work without a contract," Culp said. "If they reject the contract, we'll keep all legal options open."

Culp said the union and management are continuing to negotiate in hopes of reaching an amicable resolution.

Even though it believes it's on solid legal ground, Delta said it can't predict whether it will be able to prevent or stop a strike if its pilots choose to walk off the job if their contract is thrown out in bankruptcy court.

Delta said in its quarterly report to the Securities and Exchange Commission yesterday that it believes a strike by its pilots would be illegal, but at the same time it warned that it doesn't know if it would be able to get a court order to stop it.

Delta said it needs the $325 million in concessions it is seeking from its pilots as part of its recovery.