Pilots at United Airlines asked a federal judge on Monday to halt integration with Continental Airlines, saying the company is moving too fast in its bid to merge operations fully.
The United chapter of the Air Line Pilots Association (ALPA), which filed suit in the U.S. District Court for the Eastern District of New York, sought a stay of Friday's deadline to complete the next phase of training and begin new procedures.
The union said the proposed level and timeline of training necessary for United Continental Holdings Inc (UAL.N) to earn single operating authority from Federal Aviation Administration (FAA) is inadequate.
FAA clearance is the final step in the merger to create the world's biggest airline. The deal closed last year.
Pilots contend interrupting the deadline for new procedures would allow the union and management to either negotiate a resolution or arbitrate the dispute.
A court hearing in Brooklyn is scheduled for Wednesday.
The union said most of the training changes involve United pilots, who are adopting many of Continental's cockpit procedures.
United said the suit was without merit and was a shameful attempt to influence negotiations on a joint contract between United and Continental pilots.
"Our training procedures, which are fully approved and closely monitored by the FAA, meet or exceed safety standards and we are a safe airline," United spokeswoman Julie King said in a statement.
United's union chairman, Wendy Morse, told Reuters safety issues and the union contract are separate.
"There is a solid wall between them," Morse said.
Separately, Continental's ALPA unit announced a union rally on Wall Street on Tuesday, saying the company needed to "get serious" about negotiating a joint contract.
United officials have said they want a fair contract and have been meeting with pilots from both unions for more than a year.
Management wanted a deal in place by the end of 2011, but said over the summer the target would be missed. No new date has been set.
Without a joint contract that merges seniority and duties, the carrier cannot achieve the full measure of cost and revenue benefits forecast as part of the merger.
(Reporting by John Crawley; editing by Andre Grenon)