NEW YORK, May 15 (Reuters) - Warren Buffett's Berkshire Hathaway Inc on Monday said it added to its sizable investments in American Airlines Group Inc and Southwest Airlines Co, and shed its stake in Twenty-First Century Fox Inc.
In a regulatory filing, Berkshire said that in the first quarter it boosted its stake in American by 8 percent to 49.3 million shares worth $2.08 billion as of March 31, and in Southwest by 10 percent to 47.7 million shares worth $2.57 billion.
It also shed 8 percent of its holdings in Delta Air Lines Inc, ending the quarter with 55 million shares worth $2.53 billion.
Berkshire became one of the largest investors in American, Delta, Southwest and United Continental Holdings Inc last year, after Buffett concluded that the industry had become more efficient, with fewer unsold seats and an ability to charge for checked bags and other amenities that were once free.
The sale of the Fox stake, which totaled $251 million at year end, was completed long after the parent of Fox News became embroiled in a sexual misconduct scandal, but before its top-rated host Bill O'Reilly left the network.
It is unclear who made the Fox investment for Berkshire. Smaller equity investments at Berkshire are normally made by Buffett's deputies Todd Combs and Ted Weschler, who together recently invested about $21 billion. (Reporting by Jonathan Stempel in New York; Editing by Jonathan Oatis)