Berkshire Hathaway disclosed a new $2.6 billion investment in Delta Air Lines during the first quarter, marking a return to airline investments for Warren Buffett's conglomerate.

The investment represents a notable shift for Berkshire under CEO Greg Abel, who appears to be taking a renewed interest in the airline sector. The move comes after Berkshire had previously held and then divested airline positions in recent years.

Delta Air Lines, one of the major U.S. carriers, has been working to rebuild its operations and route network following disruptions in recent years. The airline industry has faced various challenges including fluctuating demand, operational difficulties, and geopolitical tensions affecting international routes.

The $2.6 billion stake suggests Berkshire sees value in Delta's current position and future prospects within the airline industry. The investment follows Berkshire's traditional approach of taking significant positions in companies it views as undervalued or having strong long-term fundamentals.

Berkshire Hathaway's airline investments have historically been a subject of market attention, given Buffett's previous commentary about the sector's challenging economics and capital-intensive nature.