Rossi, who has led Fidelity’s global equities team for seven years, will continue as CIO for the next seven months and plans to hand over the reins in January 2018.
The firm said it was a personal decision made by Rossi, and that he will maintain an active role as a special adviser on public policy.
Rossi said: “I am passionate about public policy and ensuring that policy making and regulation makes sense for our clients and does not have unintended consequences.
“I would like to take this opportunity to say what a privilege it has been to lead such a talented investment team and I am extremely proud of the performance and accolades that the team has delivered and won.
“I am very happy to remain in the company and to focus my attention on delivering in a different capacity.”
Rossi was responsible for the hiring of a number of portfolio managers including Jeremy Podger, Dan Roberts and Leigh Himsworth.
The firm has credited him with building the Fidelity team into one of the largest US equities teams outside North America.
