(updated with correction)
David Kaposi will join start-up manager Bastion Infrastructure Group on July 6 as a partner and head of investor relations.
Mr. Kaposi is global head of the alternative boutique of Mercer, which includes hedge funds, private equity, real estate and infrastructure investments.
Mr. Kaposi will be replaced on an interim basis by Jeffrey Schutes, global leader of manager research and wealth management, Charles Salmans, a Mercer spokesman, said in an interview.
Mercer will search internally and externally for a permanent replacement for Mr. Kaposi, Mr. Salmans said.