Abel joined Berkshire Hathaway Energy Co.in 1992 and now serves as its Chairman and CEO.
Warren Buffett and Charlie Munger will retain their positions on the board.
"They've both got Berkshire in their blood", Buffett said.
Warren Buffett's Berkshire Hathaway is adding Gregory E. Abel and Ajit Jain as directors, boosting the size of its board to 14 members. Buffett had refused to name them, but investors who follow Berkshire had long included Jain and Abel on their short lists.
Regardless, Paul Lountzis, president of Lountzis Asset Management LLC in Wyomissing, Pennsylvania, said "shareholders should be happy that these large, large contributors to Berkshire's value are now vice chairmen, and on the board".
"In terms of cryptocurrencies, generally, I can say with nearly certainty that they will come to a bad ending", the chairman and CEO of Berkshire Hathaway said. JPMorgan's Sarah DeWitt described Abel as Buffett's most likely successor, saying he "would be a strong allocator of capital and the earning power of the underlying businesses would remain strong after Buffett", viewing Jain's age as weighing on his chances.
"They know each other well, they like each other well, they both have their areas of specialty", he said.
Warren Buffett appointed two senior executives - Greg Abel and Ajit Jain - to Berkshire Hathaway's board of directors on Wednesday.
Don’t rule out Ajit Jain who runs the other half of Buffett’s business. File
For years, Buffett has said Berkshire had identified several internal CEO candidates who could replace him.
"I love what I do at Berkshire", he said.
None of the executives was immediately available for interviews. He joined the company in 1992.
While Berkshire remains best known for insurance and reinsurance, the sector generates only about one-fourth of operating results as the company has diversified. "Why in the world should I take a long or short position in something I don't know anything about?"
"If Jain become CEO it would be great, but the complexity of the insurance business requires someone there with more day-to-day supervision", Wedgewood's Rolfe said.
Mr Buffett told CNBC that the changes should be nearly imperceptible from the outside. Over the last decade, Berkshire's Buffett brought in two hedge fund managers, Ted Weschler and Todd Combs, for investing in publicly traded stocks.
Its investments include Geico, the Kraft Heinz Co, Fruit of the Loom and Acme Brick Company, as well as Northern Powergrid subsidiaries, which serve about 3.9 million customers in the UK.