Buffet Age a Concern at Berkshire Hathaway Annual Meeting

Warren Buffett may be on safari for major acquisitions, which he likes to call elephants, but shareholders may wonder if his Berkshire Hathaway Inc has become the biggest elephant in the room.

Berkshire has grown to look more and more like corporate America, as Buffett expands outside its core insurance business into such areas as energy, industrial products, newspapers, and in February ketchup, when he teamed up with Brazil's 3G Capital investment firm to buy H.J. Heinz Co for $23.2 billion.

Some investors will also ask how long a man of Buffett's age, even one who recently beat prostate cancer, can remain at the helm of the company he has led since 1965.

"There is nothing the board can do to halt the aging of the CEO, but it has no higher priority than to prepare for succession," said Thomas Russo, a partner at Gardner, Russo & Gardner in Lancaster, Pennsylvania, which invests 11 percent of its more than $6 billion of assets in Berkshire.