Pilots at Delta Air Lines and Northwest Airlines have approved a joint collective bargaining agreement.
Ratification of the agreement has been a key element of Delta's efforts to achieve a smooth integration of the two companies when it acquires Northwest later this year.
Delta's pilots union issued a statement detailing the results Monday, the deadline for rank-and-file pilots of both airlines to vote.
Northwest spokeswoman Tammy Lee says the merger should go a lot more smoothly with the contract ratification by both airlines' chapters of the Air Line Pilots Association.
"This shows overwhelming support by ALPA and their respective pilots' unions that they favor this merger. And today's vote is really a vote that sets the stage for a historical merger," said Lee. "This shows great leadership on behalf of the pilots for both companies, and it shows great promise for the future of the merger integration."
The agreement covers roughly 5,000 pilots at Northwest and 7,000 at Delta. It provides pilots with pay hikes and stock in the combined airline.
The pilots still don't have a deal to integrate their seniority lists, but have agreed to submit to binding arbitration if they can't come to terms on their own within a certain timeframe. A three-member panel has already been chosen in case arbitration is needed.
Pilots value their seniority because it determines their schedule, the aircraft they fly and layoff protection.
Delta hopes to finalize its acquisition of Northwest by the end of the year.
Still unresolved on the labor front is the union status of other workers. If the merger wins regulatory approval, flight attendants, groundworkers and other employees of the two airlines will vote to determine if they'll be unionized or not.
(The Associated Press contributed to this report)