Professor Buffett's Spring Cleaning

NEW YORK (TheStreet) -- According to his 13-F filing for the first quarter of 2010, released to the public this week, Professor Buffett has been doing his fair share of portfolio trimming.

Harkening back to Buffett's long-term, buy-and-hold investing strategy, the majority of his positions remained unchanged throughout the first quarter of 2010. The investor's top holdings continue to include Coca-Cola(KO) and Wells Fargo(WFC) which account for over 40% of Berkshire Hathaway's portfolio. Other unchanged positions included American Express(AXP), Nike(NKE), Nalco(NLC) and Wal-Mart(WMT).

Buffett did, however, decide to make a few interesting tweaks to his legendary portfolio.

One of the more interesting changes was scaling back of Berkshire's position in Kraft(KFT) by more than 20%. Although he doesn't typically explain his reasoning behind transactions, this particularly dramatic pruning likely stems from his disapproval over the firm's actions regarding the purchase of U.K. candy maker, Cadbury.

When Kraft first announced its plans to purchase the confectionary firm, Buffett immediately expressed his displeasure with the deal. As it originally stood, Kraft's stock-heavy hostile bid to takeover Cadbury was valued at $17 billion. In order to raise the necessary funds to pay for the deal, the firm sought shareholder approval to issue 370 million additional shares of KFT.

Buffett's anger toward the deal stemmed from the fear that a flood of new shares would water down the value of his 9% position in the firm and decrease his power as a shareholder.

Although Kraft appeared to bend to Buffett's concerns when it reduced the amount of shares in its final bid for Cadbury, it was still not enough to get on the investor's good side.

Aside from slashing his position in Kraft, Buffett also continued to prune his stakes in a number of prominent holdings. Johnson & Johnson(JNJ), Procter & Gamble(PG), Gannett(GCI) and Costco(COST) were among those holdings which received the biggest haircuts.

Another firm to face cuts was Moody's(MCO). Over the past year, Buffett has been consistently decreasing his exposure to the troubled ratings agency, despite telling the crowd of Berkshire Hathaway shareholders that gathered in Omaha earlier this year that he still finds the firm and its competitors attractive.

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