The Blackstone Group, the buyout and alternative assets management firm, is reportedly ready to file for an initial public offering within two weeks, in a surprise move that comes a month after peer Fortress Investment Group became the first US hedge fund and private equity group to list with a $634m (€490m) flotation.

US news service CNBC reports that Blackstone is "deep into preparations" for a flotation of shares in the management company, and has appointed Goldman Sachs to work with the firm's lawyers to develop a prospectus.