Talks to avert a strike by pilots, angered by British Airways' employment plans for a newly-formed transatlantic subsidiary, have broken down.
British Airways plans to fly to the US direct from other European cities
Union officers had met the airline at Acas, after an earlier vote in favour of industrial action by pilots.
British Airline Pilots Association (Balpa) says staff at the new carrier, BA OpenSkies, will be hired on inferior terms to those of existing workers.
BA says it would be too costly to match existing conditions at the new venture.
The airline said if strike dates were issued, it would seek a court injunction to prevent pilots taking industrial action.
"We are disappointed that Balpa has chosen to walk away from the talks led by the conciliation service, Acas," a spokesman for BA said.
"We believe the opportunity remains to reach a peaceful resolution and lift the threat of strikes from our customers."
Balpa, which represents 3,000 BA pilots, has said the terms and conditions at the new OpenSkies venture will drive down those for pilots flying BA's main fleet.
But British Airways has denied trying to undercut its pilot workforce and says the creation of OpenSkies will not "in any way affect their current pay and conditions or threaten jobs".
BA's new airline plans to offer daily flights to New York direct from Paris and Brussels from June 2008, with further routes to follow.