United Airlines Holdings Inc. (UAL  ) approached Delta Air Lines Inc. (DAL  ) about a merger last year, pursuing a combination of America's two most valuable carriers before CEO Scott Kirby's later American Airlines Group Inc. (AAL  ) proposal triggered political and antitrust backlash.

United Quietly Pursued a Delta Megamerger

The Wall Street Journal reported on Sunday, citing people familiar with the matter, that Kirby called Delta CEO Ed Bastian to pitch the transaction. Delta executives conducted preliminary due diligence and discussed its merits, but the talks did not advance and both companies moved on.

A United-Delta combination would have joined two of the world's largest airlines and brought together carriers that captured more than 90% of U.S. airline-industry profits last year, according to the Journal. Delta's premium-service strategy helped make it the nation's most profitable airline and influenced United's recent transformation.

Benzinga reached out to United and Delta for comment but didn't hear from them immediately.

Regulatory Barriers Loomed Over Potential Deal

The proposal would also have faced formidable regulatory obstacles. The Transportation Department says the Clayton Act prohibits mergers that may substantially reduce competition, while a federal court blocked JetBlue Airways Corp.'s (JBLU  ) $3.8 billion Spirit Airlines acquisition in 2024 after the Justice Department argued it would raise fares and reduce consumer choice.

Kirby's American Push Met Fierce Resistance

Kirby later pursued an even more public combination with American Airlines. American rejected the approach, saying it was not interested and that a tie-up would harm competition and customers.

President Donald Trump also opposed the proposed merger, telling CNBC, "I don't like having them merge." Sen. Elizabeth Warren (D-Mass.) separately warned that travelers could pay higher fares.

Kirby confirmed in April that he approached American, arguing the deal would add service rather than cut flights or jobs. "I was hoping to pitch that story to American, but they declined to engage and instead responded by publicly closing the door," he said.

He later said a transaction required "a willing partner" and ruled out smaller consolidation plays, including JetBlue. Delta, meanwhile, said in May it would prioritize international expansion rather than domestic consolidation.

Price Action: United Airlines Holdings shares closed 2.54% higher at $118.27 on Friday.