Colliers has been retained to market the former Core Club building at 66 E. 55th St., which is being offered for sale for $49 million, representing one of the few full-building vacant-delivery condominium offerings between Park and Madison avenues. Managing directors Zach Redding and Dylan Kane, senior associate Jared King and associate Josh Goldstern have the assignment.

Spanning nearly 40,000 square feet across six floors, the property was purpose-built as a private members’ club. With hospitality-grade infrastructure, including spa facilities, a screening room, a commercial kitchen, and private terraces, it presents a unique owner-user or repositioning opportunity across tech, healthcare, art, education or nonprofit. In addition, the property offers a Sweetgreen retail condo on the ground floor that the buyer may exclude.

The property arrives at a time when owner-occupier demand in Midtown is accelerating, driven by entrepreneurs and institutions seeking to convert rent into long-term equity, according to Colliers. 66 E. 55th speaks to a broader trend of high-net-worth buyers acquiring standalone Manhattan properties as generational balance-sheet assets, as seen in Bloomberg Philanthropies’ $560-million acquisition of 980 Madison Ave. and the Amazon purchase of 522 Fifth Ave., the company said.