A federal bankruptcy judge on Thursday denied a Northwest Airlines Corp. request to block a strike by its flight attendants that could begin as soon as Aug. 25.

Judge Allan Gropper in New York wrote that he does not have the authority to block a strike as Northwest had requested.

Flight attendants have said they may begin random, unannounced strikes after 10:01 p.m. EDT Aug. 25 unless Northwest negotiates a new contract with them. Northwest imposed pay cuts and work rules on flight attendants last month after they voted down a negotiated settlement.

"Now, Northwest management has one more chance. They have the choice to either set greed aside for once and agree to a fair and equitable contract, or they will face CHAOS," the union's acronym for "create havoc around our system," said Mollie Reiley, who runs the Northwest branch of the Association of Flight Attendants. "Management needs to reduce their demands and do it in a hurry."

A Northwest spokesman said the company did not have an immediate response to the ruling.

The union has not said what kind of strike it plans; it could range from a occasional, unannounced strikes at specific gates or flights to a full-scale walkout. The idea is that even small-scale disruptions can cause passengers to book away from an airline, giving the union leverage.

Gropper wrote that federal labor law generally bars federal courts from blocking strikes, and nothing in bankruptcy law overrides that, wrote Gropper, who is overseeing Northwest's reorganization under Chapter 11.

Northwest has negotiated settlements with its other large unions, but flight attendants have twice voted down negotiated deals that would have saved the airline $195 million a year. Flight attendants have said Northwest has asked for cuts that were too large.