Vikram Pandit, Citigroup’s chief executive, has taken another step to stamp his authority on the financial services group by picking a close ally as the company’s new chief risk officer.

The appointment of Brian Leach to replace Jorge Bermudez, a Citigroup veteran who held the position for only three months, underlined the company’s desire to overhaul its risk management practices after suffering $20bn of mortgage-related writedowns.