BOSTON-Normandy Real Estate Partners has sold 99 Summer St., a 272,614-square-foot office building here, to Cornerstone Real Estate Advisors for $110.8 million, or $407 per square foot. Normandy had paid $68.2 million for the 20-story property in 2006 as part of a portfolio, and has since renovated its five-story atrium lobby and common areas.

Cornerstone, a subsidiary of MassMutual Financial Group, is among the world's largest global real estate managers, the Boston Globe reported Thursday. It has a sizable stake in the Fan Pier redevelopment project in the Seaport District.

The sale comes as global investor interest in Boston office is on the rise. Earlier this summer, Normandy sold its Harvard Vanguard I Concord, a 49,250-square-foot build-to-suit medical office property in the Boston suburb of Concord, MA, to Cole Corporate Income Trust for $24.37 million.

Over the past 12 months alone, leasing velocity at 99 Summer reached 140,000 square feet, bringing the 26-year-old tower's occupancy to about 93%. Eastdil Secured brokered the sale of the property, known for its flame finish granite on the exterior, red pyramidal roof and stepped office design. It's located near Downtown Crossing, Post Office Square, Boston Common and the Seaport/Innovation District.

NOT FOR REPRINT

© 2025 ALM Global, LLC, All Rights Reserved. Request academic re-use from www.copyright.com. All other uses, submit a request to asset-and-logo-licensing@alm.com. For more information visit Asset & Logo Licensing.