A bipartisan group of senators, including Elizabeth Warren and Mike Lee, warned United Airlines and American Airlines that a potential merger could harm travelers through higher fares and reduced service. The lawmakers sent letters to both CEOs seeking details on how a deal would impact routes and pricing in markets where both carriers currently operate.

United-American would create the world's largest airline by multiple metrics, giving the combined entity unprecedented market power. The senators expressed concern that such dominance would allow the carrier to exploit consumers, potentially reducing competition on key routes across the country despite American's rejection of any current deal.

The letter specifically asks both airlines to share information about how a merger might affect consumers, reflecting ongoing scrutiny of consolidation in the airline industry. The request comes amid heightened regulatory attention toward potential mergers that could reduce competition in already concentrated markets.