A statement from American Airlines makes it clear the airline isn’t entertaining the possibility of a merger with rival United Airlines.

Consumer media outlets report that American Airlines said it is “not engaged with or interested in any discussions regarding a merger with United Airlines.”

American Airlines added that a merger move with UA would be “negative for competition and consumers” and “inconsistent with our understanding of the Administration’s philosophy toward the industry and principles of antitrust law.”

As reported last week, a merger between United Airlines and American Airlines would bring together two of the biggest airlines – not just in the U.S., but the world.

For that reason – sheer size alone – industry experts say any UA-AA merger would be unlikely to fly past regulatory approvals.

Earlier this month U.S. Secretary of Transportation Sean Duffy said there’s room for consolidation in the U.S. airline industry. Antitrust law experts said regulators, consumer advocates and labour unions would come at any deal with intense scrutiny.

United and American are consistently in the top three biggest airlines in the world, along with Delta Air Lines.