BNP Paribas Securities Services has axed long-standing chief executive Jacques Philippe Marson for an unspecified breach of company rules.
In a statement, the company says it "became aware that Marson had not abided by the group's rules and as a result of his actions could no longer carry out his duties as chief executive of BNP Paribas Securities Services".
The French bank insists that neither the company nor its clients had suffered any financial loss as a result of the rule breach, but declined to elaborate further.
A former Swift executive, Marson joined BNP Paribas in 1998 following a stint at States Street and played a key role in catapulting the firm into the top five custodial rankings during a period of massive consolidation in the industry.
Marson has been succeeded by Jacques d'Estais, the former head of corporate and investment banking at BNP Paribas Securities Services.