Union Investment Real Estate chief operating office Heiko Beck is to leave at the end of the year.
Part of a four-member management board, Beck will step down after four years.
The open-ended fund has more than €27bn (£20bn) of assets under management and Beck was considered a key part of the business in his time there.
Beck will not be replaced, with his role being adopted by existing board members, chairman Reinhard Kutscher, Frank Billand and Volker Noack.
Beck will move to Deutsche WertpapierService Bank to become chairman.
