Warren Buffett will step down as chairman of Berkshire Hathaway, less than a year after handing over the CEO reins, the company said Friday.

The big picture: The "Oracle of Omaha" is 96, and his insurance-to-railroads conglomerate is moving onto a new generation, with his son Howard as chairman.

What they're saying: Buffett, in a brief letter to shareholders, said the time was right to step aside from leading the board, after transitioning the CEO role to Greg Abel earlier this year.

  • "Greg runs the company; Howard will guard its culture and values – both worth more than anything on our balance sheet," Buffett wrote.
  • "Think of Howard as a policy the shareholders own and hope never to claim against."

Zoom in: Berkshire said Warren Buffett would become "chairman emeritus" and remain on the board of directors.

  • Long-time board member Susan Decker, the former president of Yahoo, will remain lead independent director.

By the numbers: Berkshire shares were flat in pre-market trading on the news.

  • The stock has underperformed this year, rising just 1% versus a gain of about 12% for the S&P 500.
  • If that doesn't change, it'd mark the fifth time in the last 10 years that Berkshire underperformed that benchmark.
  • While Berkshire has beaten the S&P by nearly 10 percentage points since 1965, in the last decade it's lagged the index by half a point or so.

Editor's note: This story has been updated with new details throughout.