The Newtown Board of Selectmen has approved the $3.1 million sale of 14 acres, eight of which will be used for senior housing, at 6 Commerce Drive.
Teton Capital Co. LLC of Old Greenwich plans to construct between 150 and 170 senior-housing apartments on the eight acres.
The property is part of a 41-acre area, 27 acres of which have been preserved as open space.
The state granted the property to Newtown for sale as a commercial development 15 years ago, with sporadic attempts at selling it coming to naught until now.
Teton must now apply for a zoning change and submit a site proposal to the town.