A former Merrill Lynch banker, who advised Royal Bank of Scotland on its disastrous merger with ABN Amro in 2007, has been promoted to be the third head of UK Financial Investments in as many years.

Jim O'Neil, who became a naturalised UK citizen after relocating from New York in 1999, has been promoted to take the top job as head of UKFI, the company set up by the UK government to manage its stake in the country's bailed-out banks.