Stephen Zinser, co-founder of ECM Asset Management, the $8.1 billion bond manager owned by US bank Wells Fargo, has decided to step down at the end of the month.

Zinser is chief executive and co-chief investment officer at ECM. In an internal memo, seen by Financial News, Zinser said: "After 15 eventful years at ECM, it is the appropriate time for me to move on and take on new career challenges."