Angus Tulloch and Jonathan Asante, star emerging-markets managers at Stewart Investors, are to step back from lead portfolio management responsibility on funds worth £11 billion in assets.

The changes at the Edinburgh-based firm, which is owned by Colonial First State Asset Management and had £20.2 billion in funds under management as of September 30 this year, are for purposes of "transparent succession planning", the company said in a statement outlining a raft of fund management responsibility switches on November 9.