Warren Buffett ended long-running speculation about his successor at Berkshire Hathaway Inc by saying Greg Abel, who oversees the conglomerate's non-insurance businesses, would be named chief executive if he were to step down.

Buffett, 90, told CNBC that "the directors are in agreement that if something were to happen to me tonight, it would be Greg who'd take over tomorrow morning."

He also said that if anything happened to Abel, it would be Ajit Jain, who oversees Berkshire's insurance businesses, would become chief executive, but Jain is about a decade older.

"The likelihood of someone having a 20-year runway though makes a real difference," Buffett said.

Buffett has never publicly signaled any plan to step down. Abel and Jain have been Berkshire vice-chairmen since 2018.

Berkshire did not immediately respond to requests for comment.

The announcement for now ends speculation that began in 2006 when Buffett, then 75, first discussed his plans for succession in his annual letter to Berkshire shareholders.Prior to becoming vice chairman, Abel was chief executive of the company's Berkshire Hathaway Energy unit.