ATLANTA -- A person with knowledge of the situation said Thursday that Northwest Airlines pilots are continuing to look for a solution to the stalled talks with Delta pilots, according to the Associated Press.

Pilots for Northwest and Delta airlines have not met for a week, but the person, who requested anonymity because of the sensitivity of the talks, told the Associated Press there's no indication they won't keep trying.

The person said the pieces of a merger are in place, held up only by the lack of a seniority agreement between the pilots at each carrier.

Unlike prior airline mergers, Northwest and Delta have tried to get their pilots to work out their own integration in advance of any airline combination. Seniority is a major issue for pilots because it determines who gets desirable (and higher-paying) planes, routes, and schedules.

Northwest's pilots' union has said seniority issues must be addressed if they're going to agree to a merger.

The proposed merger would create the world's largest airline.

Delta is the sixth-largest airline in the world and is based in Atlanta. Delta has approximately 48,000 workers and is Atlanta's largest employer.