Billionaire Warren Buffett invests in 3 big US airlines

Billionaire investor Warren Buffett has taken stakes in three large US airlines, in a $1.3 billion bet that marks a sharp U-turn of his antagonistic views on the sector.

Buffett's Berkshire Hathaway Inc invested $797 million in American Airlines , $249 million in Delta Air Lines and $237 million in United Continental Holdings, according to a regulatory filing reviewed on Monday by AFP.

Berkshire Hathaway also took a stake in Southwest Airlines, CNBC television network reported Monday.

The financial guru was known for his dislike of the airline industry after his disastrous bet on preferred shares of US Airways in 1989, calling the sector a "death trap."

The surprise Berkshire news pushed airline shares sharply higher in after-market trades. American Airlines jumped 3.5 percent, Delta was up 2.9 percent and United Continental (NYSE: UAL - news) , parent of United Airlines, gained 2.6 percent.

Buffett, the head of the massive Berkshire Hathaway conglomerate, is the world's third wealthiest person.