US multinational conglomerate Berkshire Hathaway has acquired shareholdings in several American mainline carriers company SEC filings have revealed.

In its latest disclosure, the firm said it had acquired 21.8 million shares in American Airlines (AA, Dallas/Fort Worth), 6.3 million shares in Delta Air Lines (DL, Atlanta Hartsfield Jackson), and 4.5 million shares in United Airlines (UA, Chicago O'Hare). An undisclosed number of shares in Southwest Airlines (WN, Dallas Love Field) have also been acquired, local media reported.

Berkshire Hathaway CEO and chairman Warren Buffett has, in the past, scorned returning to invest in the airline industry after US Airways (Phoenix Sky Harbor) stock he acquired back in the late '80s, declined to just 25% of their original value during the mid-90s.

According to MSNBC, although Buffett eventually made USD250 million off the deal in the end, the problems he suffered for the duration of the investment were enough to put him off the airline market entirely.