Pilots at Southwest Airlines and AirTran Airways have come to an agreement on the process to negotiate a single seniority list.

Southwest expects to close its acquisition of AirTran in the next couple of months, in a deal that will bring Southwest to Atlanta.

The deal between pilot groups does not mean the two sides have agreed on how to integrate seniority lists, but rather outlines the plan and time frame for negotiations and the potential for arbitration. Seniority is a key issue for pilots and can affect their schedules, pay and career expectations.

The agreement specifies that after 90 days of negotiations, either side can ask for mediation. If they reach a deal, a separate negotiation process would adjust AirTran pilots' pay and benefits to reflect Southwest standards, along with other changes. But if the two merger committees cannot reach an agreement by Sept. 30, 2011, it would go to arbitration. The goal would be to conclude arbitration by Dec. 31, 2011, with a final and binding award.

The deal has been signed by both pilot groups and both companies.