Worcester (Mass.) Retirement System is searching for an active domestic midcap value equities manager to run between $30 million and $40 million. RFPs will be available shortly, and the $600 million system expects to pick the new manager by the end of summer, said John Haggerty of consultant Meketa Investment Group. Funding will come from its existing equity portfolios. The search was prompted by system officials desire to get exposure to that segment of the market through an active manager; it already has passive exposure.