Warren Buffett has managed to transfer more than half of his stake in Berkshire Hathaway BRK.B +0.59% over the past 16 years, while ceding negligible control to the giant conglomerate.

This reflects a share class structure that gives excessive weight to the company’s Class A super-voting shares, in which Buffett’s stake is concentrated. Founders like Mark Zuckerberg of Meta Platforms META +0.63% (ticker: META) and Alphabet GOOGL -0.90% (GOOG) Sergey Brin and Larry Page used similar arrangements to sell shares and virtually no control.

As a result, the 92-year-old CEO retained undisputed control of Berkshire Hathaway (BRK/A, BRK/B). This agreement may help ensure that the CEO’s wishes — he hopes to avoid the collapse of the business — will be carried out for some time after his death.

The structure of the share classes was highlighted last week when Buffett donated about $759 million in shares to four Buffett family foundations. After the gift, Buffett owns 227,416 shares of Class A stock worth $107 billion: a 15.5 percent economic interest in Berkshire and 31.4 percent voting shares.

He owned 474,998 shares of Class A stock before 2006, when Buffett began his annual transfer to the Bill and Melinda Gates Foundation and four family foundations. He owned 31% of the economic stake in the company and had 37% of the voting shares, just six percentage points more than the current voting shares.

Berkshire’s two-class share structure makes this possible. Class A shares each have one vote, and Class B shares are economically equivalent to 1/1,500th of Class A shares, but have only 1/10,000th of a vote.

One factor that could prevent the breakup is opposition from whoever is overseeing the trust that owns Buffett’s stock.

Looking ahead, at some point after Buffett, Berkshire may decide to equalize the voting power of Class A and B shares to prevent an investor from gaining undue influence by buying up Class A shares.