Extell Development Seals $500M Acquisition of Block-Long Park Avenue Office Development Site

Gary Barnett's Extell Development Company has sealed the deal on a $500 million acquisition of a block-long development site at 405-417 Park Avenue in Midtown Manhattan, according to reporting from the Commercial Observer and The Real Deal. The transaction represents the largest single parcel in Barnett's growing Midtown assemblage.

Deal Overview: A Block-Long Development Site on Park Avenue

The development site spans a full block along Park Avenue between East 54th and East 55th streets, encompassing properties at both 405 and 417 Park Avenue. The site carries potential rentable office space of up to 700,000 square feet with air rights, plus 527,000 square feet of as-of-right development.

Newmark agents Adam Spies, Marcella Fasulo, and Adam Doneger represented the sellers in the offering.

Seller Consortium: GDSNY, Klövern AB, DWS, and MRP Realty

The site was brought to market jointly in August 2025 by a consortium of international and domestic real estate owners. GDS Development (GDSNY) and Swedish investor Klövern AB held interests at 417 Park Avenue, while German asset manager DWS Group and MRP Realty held interests at 405 Park Avenue.

Extell's Midtown Assemblage

For Extell Development, the $500 million acquisition represents an expansion of its Midtown Manhattan footprint. According to sources cited by The Real Deal, 405-417 Park Avenue is now officially the largest slice of Barnett's Midtown assemblage. Extell has not publicly disclosed a development timeline or program for the site.

Sources: Commercial Observer via GDSNY (gdsny.com); The Real Deal (cited by GDSNY)