Mark Roemer, a portfolio manager and director with Allianz Global Investors, is leaving after 16 years with the firm.
His last day is June 1, according to an Allianz spokeswoman.
Roemer, who joined Allianz in 2001, is responsible for running the $77.8 million AllianzGI Small-Cap Blend fund as well as the offshore Allianz US Small Cap Equity fund.
His responsibilities will be assumed by the team until Allianz finds a replacement, according to the spokeswoman.
Launched on July 1 2013, the fund has returned 24% over three years and ranks 140th out of the 243 funds tracked by Citywire in the small-cap core category.
Prior to joining Allianz, Roemer worked at Barclays Global Investors as a principal and a US equity product manager. He also worked at London-based Kleinwort Benson Investment Management.