Warren Buffett's Berkshire Hathaway Inc said on Tuesday Comcast Corp Chief Operating Officer Stephen Burke has been elected as a director, helping broaden a board that consists mainly of long-time insiders.

Burke would bring to 12 the number of directors on the board, which has attracted increasing attention in the last few years as investors wonder about Buffett's succession plan.

Burke, 51, is business-savvy, owner-oriented and keenly interested in Berkshire, the three ingredients we look for in directors, Buffett said in a statement.

A Berkshire spokeswoman did not say whether the Comcast executive -- whose family's connection to Buffett goes back several years -- would replace another director.

Burke also serves on the board of JPMorgan Chase & Co, and should have his hands full following this month's deal in which Comcast acquired a majority stake in NBC Universal from General Electric Co .

Buffett has a stake in General Electric after he bought $3 billion in preferred shares in October 2008. Berkshire had a small holding in Comcast as recently as 2007, according to regulatory filings. Berkshire has no current investment in the cable company, a Comcast spokeswoman said.

Buffett, 79, told Berkshire's annual shareholder meeting earlier this year that he has three internal candidates in mind to succeed him as chief executive.

The CEO has not hinted when he will quit, but the succession issue has cast new light on a board that some in the past have criticized as having too many insiders and friends, despite the company's success.

Half of the directors are more than 70 years old, with four older than 80, according to regulatory filings. Half of them were appointed this decade.

Burke's appointment could diversify thinking on the board and temper some of the criticism, said Bob Monks, a shareholder rights activist.

By virtue of reaching out and getting clearly intelligent, younger, interested people with a variety of experience, this expresses a sense that what's needed is ... a wider view of how this can be managed, said Monks, who has written 10 books on corporate governance.

The question is not who should replace Buffett to run Berkshire, Monks said, but rather what combination of wisdom will figure out the best thing to do with the assets that now constitute it.

That's the context in which you want to make new additions to the board, he added.

In 2007, Berkshire appointed to its board Susan Decker, 46, Yahoo Inc's former chief financial officer. Other directors include Microsoft Corp founder Bill Gates, 54, who joined in 2005; former Coca-Cola Co President Donald Keough, 83; and Berkshire Vice Chairman Charles Munger, 85.

Buffett's connection to the Burke family goes back a number of years.

Burke's father, Daniel, along with Thomas Murphy, another Berkshire director, had helped build Capital Cities/ABC.

The elder Burke retired as chief executive of Cap Cities in 1994. Berkshire was its largest shareholder. The following year, Berkshire reaped a windfall when the Walt Disney Company acquired Cap Cities for $19 billion.

Stephen Burke joins a board that last month approved a 50-for-1 split of Berkshire's class B common stock related to the planned $26.4 billion takeover of railroad operator Burlington Northern Santa Fe Corp.

Berkshire's Class B shares closed up $6.05 at $3,305.00 Tuesday on the New York Stock Exchange. Comcast shares fell nearly 1 percent to $17.20 on the Nasdaq.

(Reporting by Jonathan Spicer, additional reporting by Jeffrey Cane, Yinka Adegoke; Editing by Gerald E. McCormick and Richard Chang)