Aberdeen Standard Investments (ASI) said on Thursday that top-rated fund manager Harry Nimmo is returning to co-manage its global small cap strategy.

Nimmo stepped down as head of smaller companies just four months ago to take up another role at the firm.

The surprise change follows the departure of Alan Rowsell, investment director, and Imogen Harris, investment analyst, from Aberdeen Standard.

Nimmo will be co-manager of Aberdeen Standard’s Global Smaller Companies OEIC & SICAV and will work alongside the existing co-manager Kirsty Desson.

Aberdeen Standard managed about £470 billion of funds at the end of 2019 and is the asset management business of Edinburgh-based investment giant Standard Life Aberdeen plc.

Andrew Paisley, head of smaller companies at Aberdeen Standard Investments, said: “Harry and Kirsty have extensive experience of the strategy and global smaller companies markets.

“Harry launched the strategy in 2012 and was co-manager on the strategy between 2012 and 2017.

“Kirsty is a highly experienced portfolio manager and has been a key member of the Smaller Companies Team since 2012.

“She has been an important contributor to the Global Smaller Companies Fund and has generated some of the best ideas for the strategy.

“She has worked in the industry for over 16 years.

“We will continue to invest in the team.

“We will be recruiting a replacement investment analyst for Imogen’s responsibilities, and as already planned an investment analyst to provide both ESG support and help cover Southern Europe.

“This will further enhance our research capability.

“We would like to thank both Alan and Imogen for their contributions to our smaller companies franchise.

“Our dedicated Smaller Companies Team has a track record of success and we believe our strong team and extensive experience will ensure we continue to deliver for our clients.”

AJ Bell said the departure of Rowsell was a surprise.

“The fact that the hugely experienced Harry Nimmo has been re-appointed to the fund to work alongside Kirsty Desson is a positive given how he has managed the fund previously and been leading the small cap team until very recently,” said Ryan Hughes, AJ Bell’s head of active portfolios.

“As a result, he has first-hand knowledge of the approach and should bring important continuity to the fund.”