The City of Boston has established a public-private partnership to purchase a 207-unit apartment building in Mattapan in an effort to keep the units affordable for low- and moderate-income residents. Mayor Martin Walsh announced the city’s contribution of $4 million toward the purchase of the Morton Village Apartments, located near Morton Street station on the MBTA Fairmount Line. The deal, made through the City of Boston’s Acquisition Opportunity Program (AOP), included Avanath Capital Management, Mirak Properties and CBRE Capital Market.