Warren Buffett's company discloses new investments

OMAHA, Neb. Billionaire Warren Buffett's company has disclosed new investments in the Archer Daniels Midland (ADM) and Verisign (VRSN) as part of a busy quarter of buying and selling.

Berkshire Hathaway (BRK.A) filed the update on its U.S. stock portfolio as of the end of 2012 with the Securities and Exchange Commission on Thursday.

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Berkshire says it held nearly 6 million ADM shares and 3.7 million Verisign shares at the end of the year. Those were the newest additions to Berkshire's $75.3 billion U.S. portfolio.

Besides those new investments, Berkshire added to stakes in General Motors (GM), DaVita (DVA), DirecTV (DTV), IBM (IBM), Wal-Mart (WMT) and Wells Fargo (WFC).

Many investors try to copy Buffett's moves. But this report doesn't distinguish between Buffett's stock picks and those made by the company's two other investment managers.