Merger talks between Delta Air Lines and Northwest Airlines picked up pace again on Sunday, and people briefed on the negotiations said an announcement of a deal could come as soon as Tuesday.
The two companies have seemed on the verge of announcing a deal several times in recent months — raising hopes among some investors and worrying those concerned about loss of competition among airlines — only to back away from a merger.
During that period, the airline business has deteriorated sharply. Record-high fuel prices have sent a handful of smaller carriers into bankruptcy in recent weeks. The latest was Frontier Airlines on Friday.
Some analysts now expect the industry to lose money this year after two years that were mostly profitable. And the slowing economy is making it hard for airlines to raise fares to cover fuel costs.
A representative at Delta could not be reached and a Northwest spokesman declined to comment.
Shares in Delta and Northwest have plunged since they emerged from bankruptcy about a year ago. Delta closed at $10.01 on Friday, down from a high of $21.95 last spring. Northwest closed at $10.96, down from a high of $26.50 last spring. If the deal was structured as a stock acquisition of Northwest by Delta, it would be worth Northwest’s market capitalization of $2.59 billion.
The broad outlines of a deal have remained constant: an exchange of stock at a ratio close to market prices; a combined airline that would be called Delta, with headquarters in Atlanta; and Richard H. Anderson, Delta’s chief executive, keeping that position, with Northwest’s chief executive, Douglas M. Steenland, stepping aside.
Pilots at Delta and Northwest earlier could not agree on how to merge their seniority lists, which is important to them because it determines their ranking for pay, what kind of plane they would fly and their days off. So last month, Northwest asked Delta to proceed toward a deal without a combined list.
The carriers had hoped to get a merged list before a deal so that operations could be combined quickly and without rancor. US Airways and America West Airlines have been unable to fully combine operations more than two years after merging because of disputes over a seniority list.
Pilots have no legal power to block a merger, but they could appeal to lawmakers to help prevent a deal.
James L. Oberstar, chairman of the House Transportation and Infrastructure Committee, has said he opposes big airline mergers because competition would suffer and some markets would lose service.
Putting a deal together now without a merged pilots list and amid an industry downturn could be difficult. The carriers had promised the pilots a raise and a lot of stock in the merged airline in exchange for a combined seniority list.
Leaders of the Delta and Northwest pilots’ unions met separately over the weekend. There was no immediate action by either union.