Osman Semerci, one of Merrill Lynch's top bankers in Europe who was part of the shake-up that saw management of the investment bank move away from its traditional Wall Street base, has left the firm ahead of an expected third-quarter write-down of $1.5bn (€1.1bn) in its fixed income business.

Semerci has been replaced by David Sobotka, senior vice-president and head of the global commodities group based in New York. Sobotka joined Merrill in November 2004 when the bank re-entered energy trading with its acquisition of the trading businesses of Entergy-Koch, the US energy company.