Airlines are trying to cut costs as fuel prices surge
Delta Air Lines and Northwest could seal a deal imminently, to create the world's largest airline, reports say.
Officials were preparing to make an announcement about the completion of a deal as early as Tuesday, said the Associated Press, citing sources.
However, union leaders have highlighted pilots' contracts as a sticking point between both sides.
Rising oil prices are forcing airlines to cut costs. Delta has said it would eliminate 2,000 jobs this year.
Airlines worldwide are suffering in the wake of a consumer slowdown in the US and Europe, making it harder to raise ticket prices at the same time as their fuel costs are also climbing.
Union leaders, who met this weekend, said any deal would have to ensure "fair and equitable seniority list integration".
Seniority integration refers to which pilots would be selected to fly which routes and on which planes.