Northwest Airlines has declared an impasse in negotiations with its mechanics union on a deal that would save the carrier USD$176 million annually, the Aircraft Mechanics Fraternal Association reported on its web site.

The union said in a statement posted Wednesday that the airline has asked the National Mediation Board to call for a 30 day cooling off period.

In a letter to the mediation board, the airline complained that after six months of negotiations the union remains unwilling to agree to a proposal and refuses to acknowledge that such labor savings are needed.

The union said its previously scheduled meeting with the mediation board to discuss negotiations will be June 2.

"We view this as a significant step towards midsummer wage resolution, though one likely at first to be greeted negatively as some buy into media-perpetuated strike hype," wrote JP Morgan airline analyst Jamie Baker in a research note.