New York-based derivatives broker MF Global has appointed a new chief operating officer, continuing an overhaul of much of its senior management since a Memphis-based employee lost $141m in allegedly unauthorised wheat trades in February. The firm has replaced its chief executive, chief financial officer, chief risk officer, chief compliance officer, chief information officer and treasurer since that incident.

The London-based Karel Harbour, who joined MF Global in 2002, previously was the chief operating officer for the company's European entities. In his new role, he will be responsible for operations for all MF Global entities in more than a dozen countries and will report directly to Bernard Dan.