By Colin Barr

    Starting Thursday, investors will be able to bet on famed investor Warren Buffett's company without breaking the bank.

    Shareholders of Buffett's Berkshire Hathaway (BRKA, Fortune 500) met Wednesday to approve a stock split covering one class of Berkshire shares. Effective Thursday morning, the split will cut the price of these shares to around $66 each, from a recent $3,300.

    The move, which was approved last year by Berkshire's board, could attract some new investors by eliminating the sticker shock long associated with Berkshire shares.

    It could also, some observers have suggested, pave the way for Berkshire to join the S&P 500 since it would increase the amount of shares outstanding. The people in charge of maintaining the S&P 500 have typically been wary of adding stocks with low levels of liquidity.

    Berkshire has two classes of stock: Class A shares that recently traded for around $101,700 each, and the Class B (BRKB) shares that are to be split 50-for-1. The Class A shares won't be affected by Wednesday's vote.

    Berkshire asked shareholders to approve the split so it could offer Berkshire shares to all investors in Burlington Northern (BNI, Fortune 500), the railway company Berkshire agreed in November to acquire in a deal valued at $34 billion in cash and stock. The deal is scheduled to close early this year.

    Splitting the Class B shares will make it cheaper for investors to take Buffett's side in the Burlington bet, which he called an "all-in wager on the economic future of the United States."

    The split would mark the second time in the company's 45 years under Buffett that it has made some of its shares more affordable.

    In 1996, Berkshire sold the cheaper Class B shares to the public for the first time. The company said it made the move in response to the plans of some investment companies to sell products that would let investors invest in Berkshire without paying the full price of a Class A share, then around $35,000.

    At the time, the value of the Class B shares was fixed at 1/30th of a Class A share. That will change to 1/1,500th with Wednesday's vote. Class B shares also carry reduced voting rights and can't be converted into Class A shares.

    Buffett warned in his 1996 letter to shareholders that the proposed "Berkshire look-alikes" from other investment firms would have tried to "entice naive small investors and would have charged these innocents high fees and commissions."

    Buffett said that the 1996 offering, which raised $565 million for Berkshire, was "generally successful" in drawing in shareholders who would hold the stock for the long term. He said it added about 40,000 shareholders to Berkshire's rolls.

    Trading in the Class B shares was light initially, with daily volume rarely rising above a few thousand shares through 1997 -- a fraction of the trading in the more expensive Class A shares.

    But as Berkshire began using the Class B shares for acquisitions in the late 1990s, trading picked up. Average daily trading volume in the Class B stock has exceeded a million shares in every month since December 2005. Trading in the pricier Class A shares, by contrast, has only rarely exceeded 300,000 shares.