OMAHA, Neb. -- Billionaire investor Warren Buffett's Berkshire Hathaway Inc. disclosed that it bought 3.73 million shares of ServiceMaster Co., a stake that regulators said Berkshire could no longer keep confidential.
Berkshire owned 3.05 million shares at the end of 2003 and bought 680,600 more shares in the six months through June 30, revised filings with the Securities and Exchange Commission showed. They also revealed a 5-million-share stake in Comcast Corp. that Berkshire had already reported in filings with state insurance regulators.
Buffett's company, based in Omaha, Neb., had argued that the stocks it bought or sold be kept secret because copycat investing increased its trading costs.
Berkshire bought both stakes through its Geico Corp. auto insurer, whose portfolio is managed by Louis Simpson. Buffett has mentioned Simpson as a potential successor as head of Berkshire's investments.
The SEC earlier this month denied Berkshire permission to withhold disclosure of its holdings of ServiceMaster, which owns and franchises lawn-care and pest-control centers. The SEC didn't name the stock at the time.
As of June 30, Berkshire's stake was valued at $46 million.