Rambleside Holdings LLC sold The Brewster, a 144-unit apartment building at 21 West 86th Street, to an institutional buyer and operator for $98 million.

The building is one of the last pre-war residential properties on the Upper West Side that hasn’t been converted to condominiums. It contains 116,000 sq. ft. of space, including more than 10,000 sq. ft. of professional space occupied by Columbia University, and offers views of Central Park.

CBRE Inc. represented the seller in the transaction.

“Rambleside recognized the current lack of available multi-family product for sale in Manhattan and decided that now was an opportune time to sell,” said CBRE Vice Chairman Darcy Stacom in a statement. “The buyer was able to secure the asset in the marketing process by formulating a leasing strategy that would tailor to the Upper West Side rental market while continuing to renovate the property. This transaction continues to show the value of a well-run auction versus recent off market trades.”