Citigroup has hired Michael Hampden-Turner, senior structured credit and derivatives research analyst at The Royal Bank Of Scotland in London. Hampden-Turner was on gardening leave and could not immediately be reached. He will report to Matt King, managing director and head of quantitative credit strategy at Citigroup in London, who declined all comment. Siobhan Pettit has taken over his responsibilities and RBS reportedly has added several quantitative analysts, but names and numbers could not immediately be determined. Shaun Gamble, RBS spokesman, did not return a call.