The Securities and Exchange Commission, the US regulator, is faced with four major vacancies in its senior ranks following the announcement that Meyer Eisenberg, deputy general counsel and acting director of the mutual funds regulation unit, will resign next month.

Giovanni Prezioso, the SEC's general counsel, said last month he will resign early next year to return to the private sector; the post of permanent chief accountant post has not been filled since the departure in October of Donald Nicolaisen and Annette Nazareth has yet to be replaced as permanent head of the market regulation division, after she became an SEC commissioner in August.