Brookline (Mass.) Retirement System plans to invest in active emerging markets equities for the first time, with the $225 million system looking to hire a manager to run $8 million to $12 million, said Frank Zecha, executive director. All cap sizes and styles are being considered. Funding could come from an assortment of the funds other holdings depending on what the market is doing when the selection is made, but the system doesnt plan to terminate any existing managers, Mr. Zecha said. Meketa Investment Group is assisting. A manager should be chosen before the end of July, Mr. Zecha said.