Six United Airlines pilots who flew for Continental before the carriers’ 2010 merger have sued their union, claiming it favored the larger airline during protracted negotiations over seniority, which determines everything from their pay to their work schedules to the type of aircraft they fly.

The class-action lawsuit, filed Monday in the U.S. District Court in Houston, accuses the Air Line Pilots Association, International of breaching its duty to provide fair representation to the former Continental pilots by diminishing their seniority in favor of pre-merger United pilots. The merged seniority list was released in September following lengthy and contentious negotiations. Seniority determines not just pay but also rank, scheduling and routing. It also enhances job security during industry downturns.

The lawsuit alleges many Continental pilots lost years or decades of seniority when the two groups were integrated. The lawsuit seeks to restart the process with no favoritism toward pilots who worked for United before the merger.

Michael Carr, who began flying with Continental in 1996, said he was ranked 14 percent lower on the combined list and that many former United pilots with lower ranks and experience are ranked higher. He said other fellow Continental pilots dropped even further.

“The thing was tilted so far in their favor it was absurd,” said Carr, one of the plaintiffs. “We are required to pay thousands of dollars a year to be a member and we essentially have no voice.”

The Air Line Pilots Association, International represented both pilot groups before the merger and now represents the combined workforce.

Carr said the disgruntled former Continental pilots have lost confidence in the union.

“It’s like nobody is representing us,” he said. “We have a vote but it doesn’t really count.”

The lawsuit alleges the union had political incentive to favor the United pilots because they had enough votes to switch to a different union if they didn’t get their way. At the time of the merger, United had about 7,700 pilots and Continental about 4,640. Nearly all of these pilots now work for the post-merger United, the lawsuit states.

The Air Line Pilots Association, International called the lawsuit unfounded.

“The seniority arbitration was fair and equitable,” the union said in a statement. “It was conducted by three nationally respected labor arbitrators with both pilot groups represented by their own very experienced lawyers. The lawsuit is completely without merit.”

Following the United-Continental merger, the union began the process to combine the seniority lists. The lawsuit claims that the union assisted United pilots with discovered and paid a witness to appear for United pilots. It also claims that the attorney appointed for Continental’s pilot group had ties to the union.

The lawsuit states that In 2005, the union lost members following a merger between U.S. Airways and America West when U.S. Airways pilots voted to switch to a new union over negotiations that favored the America West pilots.

“This union had been burned once before and, instead of seeking a fair resolution for all its members, it ignored its duty to be fair by repeatedly poisoning the process simply to favor the side with more political clout,” Adam Milasincic, the Continental pilots’ attorney, said Tuesday. “This caused enormous loss to the former Continental pilots.”

Photo Credit: United and Continental pilots march on Wall Street in September of 2011. Dan Nguyen / Flickr