Updated with correction.
T. Williams Roberts III's name was misspelled in a version of this story that ran in the June 28 P&I Daily.
Thomas F.X. Powers and T. Williams Roberts III, partners and co-presidents of GW&K Investment Management, were named co-CEOs of the firm effective July 1, a spokeswoman said in an email.
They replace Harold G. Kotler, who is stepping aside as CEO and has been named chairman of the firm. Mr. Kotler, a founder of the firm, will continue to serve on the executive committee.
Messrs. Powers and Roberts will continue in their prior responsibilities, the spokeswoman said.
Mr. Powers currently oversees sales, marketing and relationship management, and Mr. Roberts oversees business operation functions, including finance and compliance.
As of March 31, GW&K had $51 billion in assets under management.