The transaction
JLL, which ran the sale process, announced on August 24, 2026 that One Marina Park Drive in Boston's Seaport District had traded for $435 million. The buyer was Oxford Properties; the seller was Clarion Partners.
The building runs to 494,938 square feet across 18 stories and was 99% leased at the time of sale. Delivered in 2010, it was the anchor asset of The Fallon Company's $4 billion Fan Pier development and carries LEED Gold certification.
JLL described it as the largest pure-play office sale in Boston in five years. A cap rate was not disclosed in the materials reviewed.
Why the buyer is the story
Oxford Properties, the real estate arm of Canadian pension investor OMERS, sold out of global office at scale between 2018 and 2022, recycling roughly $14 billion out of the sector. It has deployed about $2 billion back into office globally since the start of 2025, and this was its first core US office acquisition in nearly a decade.
Analysis: the significance is not that one building changed hands, but that an institutional investor that had systematically exited the asset class re-entered it at the top of the quality spectrum. A fully leased, sixteen-year-old, certified tower in a waterfront innovation district is the narrowest possible definition of office risk.
That distinction should temper any reading of this deal as a broad office recovery. Capital returning to the best-leased buildings in the strongest submarkets tells you very little about the pricing available to owners of half-empty 1980s stock.
Other large office trades this summer
The Boston deal was not isolated. In Los Angeles, Bank of America Plaza sold for $210 million in a receivership sale reported June 16, 2026, described as the largest LA office sale of the year.
In Houston, Williams Tower was bought by its tenant, Williams Companies, for more than $300 million, closing July 20 and reported July 22 as the largest single-property Houston office sale since 2019. In Phoenix, Esplanade III traded for $86 million on August 26, the largest single-building office deal in that market in 2026.
The list spans very different transaction types — a stabilised institutional trade, a receivership, an owner-occupier purchase and a mid-size sale — which is itself the point. Office liquidity in 2026 is returning through distinct channels rather than as a single market.
Handle the superlatives carefully
Each 'largest since' claim above originates with a broker or a local trade publication working from its own transaction database, not from an independent national ranking. These databases differ on what counts as an office sale, whether partial-interest trades are included, and how mixed-use assets are classified.
One currency point is worth flagging for readers who encounter the Boston deal in Canadian coverage: it was reported there at roughly C$599.6 million, which is the same US$435 million figure converted, not a second price.
Without disclosed cap rates or price-per-square-foot comparisons across these deals, the honest conclusion is limited: large office assets are trading again, at prices sellers were willing to accept, and in Boston's case to a buyer that had spent years avoiding them.