Seven former heads of the Securities and Exchange Commission have backed the US regulator's proposal that all mutual funds have independent chairmen, a plan opposed by many in the $7.5 trillion (€6.2 trillion) fund industry.

The US mutual fund industry has been rocked by scandal in the past year after regulators uncovered improper trading by hedge funds that harmed long-term shareholders. Firms involved in the scandal have paid over $2.3bn in fines to date.