New York City Employees Retirement System and the New York City Teachers Retirement System issued a joint RFP for an activist investment manager, according to the New York City Retirement Systems website. Joseph Haslip, assistant comptroller, did not return calls seeking additional information. Officials of the $38 billion employees fund and the $33.9 billion teachers fund will consider U.S., international and global equity strategies from firms with at least $50 million in institutional activist investments under management. Activist strategies often purchase a substantial equity position in each company in a portfolio and then work with directors and management teams to improve performance. Proposals are due May 30, and a selection is expected by December.