Whiteoak joined Axa Framlington back in 2000 and has led the £133m smaller companies fund to top quartile performance in the sector over five year as well as the Throgmorton Trust Plc. He also received a AAA rating from ratings agency OBSR.
He will be replaced by deputy manager Chris St John wih Brian Watson taking on the deputy role.
Axa Framlington chief executive Robert Kyprianou says: “Chris St John is a highly talented investor and is well respected by his peers. As our primary fund manager for our institutional small and mid cap strategies Chris has demonstrated his skills and investment expertise.
“After seven years with the company, we would like to thank Roger for his contribution and wish him well in his future endeavours.”