United CEO pitches American merger

Kirby argued that the merger is necessary for U.S. airlines to compete effectively against foreign carriers on international routes.

However, the proposal has immediately drawn fire from consumer advocates and labor unions who warn of higher fares and reduced competition.

Shares of both airlines climbed following the news, though analysts expect any formal deal to face an extraordinary antitrust roadblock.

The pitch comes at a critical time for the aviation industry as it grapples with surging jet fuel costs linked to the Middle East conflict.