In late 2011, UBS Realty Advisors acquired 53 State St., also known as Exchange Place, for $610 million, according to a report in the Boston Business Journal.

The 1.24 million square-foot property integrates the historic Boston Stock Exchange Building that was completed in 1891 and the 40-story modern glass office tower built in 1985. The property includes a seven-story, glass-enclosed atrium, an outdoor arcade with seating areas along Congress Street and tenant-dedicated amenities.

The building has achieved platinum-level certification from LEED Dynamic Plaque.

“Allianz recognizes this acquisition is a unique opportunity to expand into Boston and to continue to diversify our investors' portfolio. This new joint venture enables us to deepen our relationship with Beacon, and to engage with our new partner, Mass. PRIM,” says Christoph Donner, CEO of Allianz Real Estate of America.

Allianz reports it now owns a 49% interest in the property.

The transaction closed on Dec. 6. Building management and operations are provided by Beacon Capital and Newmark Knight Frank. The leasing agent for 53 State St. is Newmark Knight Frank.

“53 State Street is a high-quality acquisition and another example of PRIM's strategy of investing in excellent properties with potential for long-term gain,” says Massachusetts Treasurer Deborah Goldberg, chair of the PRIM Board, which oversees the $70-billion Massachusetts State Pension Fund. “Our partnership with Beacon and Allianz continues our collaboration with exceptional partners and we are pleased to be working with them as we move forward.”

Michael G. Trotsky, CFA, executive director and chief investment officer of Mass. PRIM, adds, “Our real estate portfolio includes some of the top office buildings in the U.S., and this investment is consistent with our overall strategy to generate strong returns from Class A properties.”