Christopher Cox, chairman of the US Securities and Exchange Commission, has warned Congress that any taxes imposed on private equity firms could impact fundraising, as Blackstone's $5.1bn (€3.8bn) initial public offering sparks fresh scrutiny of the industry.

In a hearing before the House Financial Services Committee Cox said: "The taxes on public investment companies as compared to private companies can affect capital formation. Any discrimination between public and private companies could discourage companies from going public."