Delta Air Lines Inc. and Northwest Airlines Corp. may unveil their long-delayed merger announcement as early as Tuesday, said people familiar with the matter, in the latest move by airlines to grapple with high fuel prices and a softening economy.

The deal could value Northwest at roughly $3 billion, these people said, though terms were still being negotiated. That would be well below Northwest's market value of more than $4.6 billion as of Feb. 1, reflecting the industry's worsening prospects in recent weeks.

Please don't devalue my mileses.