France's Societe Generale is planning an initial public offering for its broker-dealer unit SG Cowen, the New York-based firm that provides an array of investment services, including underwriting, equity research and merger advice. Societe Generale expects to file a registration statement with the Securities and Exchange Commission in the first quarter and hopes to complete the IPO later in 2006. SG Cowen was formed in 1998 when the financial-services firm Societe Generale acquired Cowen & Co. The division has made a name for itself in recent years by offering investment-banking services in sectors such as health care, technology and telecommunications. The Wall Street Journal reported that the IPO would probably be valued at $300 million to $500 million.