IPE Real Assets understands that Mass PRIM will own a 49% stake in Exchange Place. : The Exchange Place skyscraper in Boston has been sold for $845m (€743.5m) to Massachusetts Pension Reserves Investment Management Board (Mass PRIM) Allianz Real Estate, and Beacon Capital Partners. In December 2011, UBS Realty Investors bought the 53 State Street office tower in Boston’s financial district from Brookfield Office Properties for $610m. Media reports this year indicated that UBS was planning to sell the 40-storey tower. IPE Real Assets understands that the $71.7bn Mass PRIM pension fund will own a 49% in the 1.24m square-foot asset.