Allianz Global Investors has announced George McKay will step down from his responsibilities next April.
Mr McKay is currently the firm’s co-head, global chief operating officer and global head of distribution.
The firm has appointed Karen Prooth to take over the role of global chief operating officer.
She will join the firm on 1 November from BlackRock, where she was global platform head for ETF and index investments.
Mr McKay said: "We are delighted to welcome Karen to AllianzGI. She brings many years of outstanding leadership experience to this critically important role.
"In addition to being instrumental in ensuring our operational agility and efficiency as we continue to build our global active offering and to innovate on behalf of clients across asset classes, I know that Karen will make a significant contribution to the development of our company as a people-focused business, and she will play an active role in building on our already strong culture."
Mr McKay has worked at AllianzGI since 2006 and as global COO since 2012.
Since March 2016, he has also been responsible for global distribution and has been co-head of the firm alongside CEO and global chief investment officer Andreas Utermann.
His global distribution responsibilities will be taken over by Tobias C Pross, currently head of EMEA, from 1 April 2018.
Mr Pross has held a number of senior roles in distribution and client advisory since joining Allianz’s asset management division in 1999.