The 36-story luxury residential rental at 800 Sixth Ave. between West 27th and 28th streets is in contract to Greystar for $240 million.

Developed in 2003 by the Adell family’s Adelco, which had rezoned the old Flower District, the Archstone Chelsea has 266 apartments of which 62 are still rent-stabilized, a roof deck, a fitness center and an easy walk to NoMad and Herald Square.

The seller, Equity Residential, obtained it in 2013 as part of its $16 billion joint purchase with AvalonBay of the Archstone-Smith portfolio from Lehman Bros. Lehman’s $23.7 billion buy of Archstone in 2007 had contributed to its collapse.

Douglas Harmon, Adam Spies and Marcella Fasulo of Cushman & Wakefield marketed the property for Equity, and previously did so for Adelco to Archstone. Last year, the team sold Equity’s 101 West End Ave. for $416.5 million to Dermot and PGGM.

Greystar is the largest manager of residential apartments in the country with more than 150,000, while Equity now has 79,260.

Cushman & Wakefield declined to comment, while Equity and Greystar reps did not immediately reply.