By Jonathan Stempel
(Reuters) - Warren Buffett's Berkshire Hathaway (NYSE:BRKa) Inc on Friday said it has boosted its holdings in some of the billionaire's favorite companies, including Wells Fargo (NYSE:WFC) & Co and International Business Machines (NYSE:IBM) Corp.
The changes were disclosed in a regulatory filing detailing Berkshire's U.S.-listed stock portfolio as of March 31.
Berkshire also boosted its share stake in U.S. Bancorp, another large holding, while other portfolio managers adjusted their stakes in several companies.
No new stocks were added to the portfolio, which shrank to $107.1 billion from $109.4 billion in December. Berkshire bought $1.62 billion and sold $1.11 billion of equities overall.
Buffett has long praised his "Big Four" stock holdings Wells Fargo, IBM , Coca-Cola Co and American Express Co (NYSE:AXP), which comprise roughly 58 percent of Berkshire's equity investments.
Buffett has stuck with them despite recent adversity including IBM's stagnant stock price, concern over Coca-Cola's sugary products and executive pay structure, and a February court ruling that American Express violated antitrust law.
"Too many fund managers are more interested in seeing stocks to which they have committed perform well" in the short term, said Andy Kern, a University of Missouri professor who teaches a class on Buffett's investment strategies. "Berkshire has such a long time horizon that it can afford to watch the stock price go down so it can buy more."
Friday's regulatory filing does not disclose who makes which investment at Berkshire. Smaller investments are often made by portfolio managers Todd Combs and Ted Weschler, who may succeed Buffett as chief investment officers after he departs.
In the first quarter, Berkshire raised its stake in Wells Fargo by about 2 percent to 470.3 million shares, and in IBM by roughly 3 percent to 79.6 million shares. The U.S. Bancorp stake grew about 5 percent to 83.8 million shares.
Other holdings that grew include Deere & Co, Liberty Global (NASDAQ:LBTYA) Plc, Phillips 66 (NYSE:PSX), Precision Castparts Corp (NYSE:PCP) and Twenty-First Century Fox Inc.
Holdings declined in Bank of New York Mellon (NYSE:BK) Corp, Charter Communications Inc (NASDAQ:CHTR), National Oilwell Varco Inc (NYSE:NOV), Viacom Inc and Wabco Holdings Inc.
Berkshire also owns more than 80 businesses, including the Burlington Northern railroad, Dairy Queen ice cream and Geico car insurance.
Buffett, 84, this month celebrated his 50th anniversary running his Omaha, Nebraska-based company, whose market value is fifth-highest among publicly-traded U.S. companies.