The influential rainmaker, who joined Lazard from Lehman a little over three years ago, resigned in the past few days, say sources, without having tied up a new position.
There is speculation that de Rosnay, who specialises in the healthcare sector, may turn up at Bank of America Merrill Lynch, a bank that has hired a number of big names from the former Lehman operations including Christian Meissner, its new global head of investment banking.
De Rosnay’s departure will leave Nicholas Shott as the sole head of UK investment banking, while William Rucker remains chief executive officer of the London Lazard operation. The firm recently enhanced its investment banking team by hiring Noah Bulkin from BoA Merrill Lynch.
While at Lazard, de Rosnay helped advise SSL, the condoms to Scholl shoes manufacturer, on its $3.8bn takeover by Reckitt Benckiser Group.
He has advised drugmakers including Teva Pharmaceutical Industries and Novartis. Shott is a former newspaper executive and a long-standing adviser to ITV.