(Bloomberg News) Oaktree Capital Group LLC, the world's largest distressed-debt investor, filed to raise as much as $517.5 million in an initial public offering.

The firm plans to sell 10.3 million shares at $43 to $46 each, Los Angeles-based Oaktree said today in a filing with the U.S. Securities and Exchange Commission. Some of its existing shareholders, including Clipper Fund Inc., will sell nearly 1 million shares.

Oaktree expects to receive about $426 million from the IPO if the shares are priced in the middle of the range. All of the proceeds Oaktree receives will be used to buy interests from the firm's principals, employees and investors, it said in the filing.

The firm was started in 1995 by Howard Marks and six partners from Los Angeles-based investment firm TCW Group Inc. Marks, 65, is a billionaire who owns about one-sixth of Oaktree. He named the firm for the English translation of his Santa Barbara, California, weekend home, Las Encinitas.

Oaktree, which managed about $75 billion as of Dec. 31, is selling shares in the wake of mixed results from leveraged- buyout firms Blackstone Group LP, Apollo Global Management LLC and KKR & Co. since they went public. Oaktree raised about $1 billion in May 2007 when it sold a 15 percent stake on the private exchange run by Goldman Sachs Group Inc., a transaction valuing the company at $6.3 billion.

Underwriters of the IPO have the option to purchase another 15 percent of the total shares being offered by Oaktree and the selling shareholders, the filing shows.

Blackstone, the world's largest private-equity firm, raised $4.1 billion in its 2007 IPO, a year before the collapses of Bear Stearns Cos. and Lehman Brothers Holdings Inc. The shares have fallen 50 percent since. Apollo has declined 24 percent from its offering a year ago. KKR has risen 40 percent in New York trading since its July 2010 share sale. Carlyle Group LP is preparing to go public as well.

Goldman Sachs and Morgan Stanley are among underwriters for the offering, according to the filing. The shares will trade on the New York Stock Exchange under the ticker symbol OAK.