Just a few months after Delta Air Lines pilots voted against a proposed labor contract, Southwest Airlines pilots rejected their tentative agreement.
That means the two sides will return to the bargaining table, with Dallas-based Southwest saying it expects mediated talks to resume in spring 2016. Southwest and its pilots have been in contract discussions for more than three years, and in mediation since November 2014.
Delta and Southwest are the No. 1 and No. 2 largest airlines at Hartsfield-Jackson International Airport.
The Southwest pilots union said 61.64 percent of those who cast ballots were against ratifying the agreement. More than 95 percent of members cast ballots.
"Despite increased compensation and some work rule improvements, there were new company allowances in this agreement that our pilots did not find palatable when compared to the potential gains," the union said in a written statement.
The union said it is "willing to meet with company management at any time" to work toward a deal.
Southwest pilots, like Delta pilots, will continue working under their current contract.