Billionaire Warren Buffett will remain chairman of Berkshire Hathaway after Greg Abel takes over as CEO at the start of the new year.

Buffett to remain as chairman. "Buffett leaves a company that is less reliant on his investing capabilities, with an array of leading businesses with strong cash flows," said Brian Meredith, UBS' Berkshire analyst.

Although Abel's expected ascension had been known for four years, the announcement at Berkshire's annual meeting in Omaha, Nebraska, was a surprise.