The buildings total 182,000-sf including retail, trading for the impressive mark of about $425 per sf. Cushman & Wakefield had been handling the negotiations on behalf of Heritage, but officials there did not respond to inquiries regarding details of the transaction. Efforts to discuss the situation with Heritage and Westport Point Capital officials were also unsuccessful by press deadline.

Westport, which is headquartered in 535 Boylston St., was founded last June by Erin O'Boyle and Mary Lou Boutwell, two Boston-area real estate veterans who subsequently entered into an exclusive partnership with Prudential Real Estate Investors to acquire commercial real estate in metropolitan Boston. Earlier this year, the partnership bought 70 Franklin St. in Boston's Financial District for $21.5 million and has indicated goals of acquiring upwards of five more assets locally in the coming year.

Heritage Commonwealth LLC is an affiliate of Centros Properties Group, an Australian investor that acquired 535 and 545 Boylston St. when it gobbled up Heritage Property Investment Trust last summer for a price estimated at $3.2 billion. As in many such deals, Centros has been harvesting some of those assets. The per-sf price was "impressive," says one investment broker active in Boston, particularly given the age of the buildings. The 13-story 535 Boylston St., which has 90,000 sf of office space, dates back to 1968, while 545 Boylston St. was developed in 1973. That property has 85,000 sf of office space.