Meredith Whitney, the analyst whose prescient bearish warnings on Citigroup and other banks have earned her a strong following on Wall Street, is leaving Oppenheimer & Co to set up her own research and advisory firm.

Ms Whitney, whose warning in 2007 about Citigroup's capital shortfalls wiped hundreds of billions of dollar off its market capitalisation and was followed shortly by the resignation of Chuck Prince as chief executive, said the move did not mean she was any less bearish on prospects for the banking sector.