Berkshire Hathaway sold all of its stakes in the United States' four biggest airlines last month, the conglomerate's chairman and CEO Warren Buffett revealed at its virtual annual shareholders' meeting on May 2.

He said that “the world has changed” because of the coronavirus and that he had been wrong to invest so heavily in the aviation industry in the first place, Reuters news agency reported.

The company, which began investing in the four airlines in 2016 after avoiding aviation for years, announced a record USD49.7 billion net first-quarter loss due to the overall impact of the pandemic. Its operating earnings, which exclude investments and derivatives, improved however, to USD5.87 billion, according to Associated Press.

It had held an 11% stake in Delta Air Lines, 10% of American Airlines, 10% of Southwest Airlines, and 9% of United Airlines, according to its annual report and company filings.

“We will not fund a company where we think that it is going to chew up money in the future,” Buffett pledged at the meeting.

Buffett said that Berkshire Hathaway had invested USD7 billion to USD8 billion on the stakes in the four carriers. But the divestments began on April 3, when Berkshire Hathaway disclosed it had sold around 18% of its Delta shareholding and 4% of its Southwest stake.

He said that before the crisis he had been considering further investments in airlines.

“I was wrong about that business because of something that was not in any way the fault of four excellent CEOs,” he said, according to CNBC. “I mean, believe me, no joy being a CEO of an airline. But the companies we bought were well managed. They did a lot of things right.”

American, Southwest, and United have declined comment, but Delta said in a statement: “While we cannot speak to individual shareholders’ decisions around buying and selling shares in Delta, we have tremendous respect for Mr Buffett and the Berkshire team.” It added: “We remain confident that the strengths that are core to Delta’s business - our people, our brand, our network, and our operational reliability - will endure and position Delta to succeed as a better, stronger, and more resilient airline in the future.”