A listing on the Web site of Ginnel Real Estate refers to the three-story, 10,000-square-foot colonial-style home, in the Mount Kisco area, as a “state-of-the-art and eco-friendly country estate” with geothermal heating and cooling, energy-efficient appliances and fiber-optic lighting. It sits on 10 acres on South Bedford Road.

Muffin Dowdle, the agent listed as managing the sale, did not respond to requests for comment.

The names of Mr. Kennedy and his estranged wife, Mary R. Kennedy, appear on a deed for the property, as well as on a record of a $500,000 mortgage taken out on the residence in June 2010.

The Kennedys were embroiled in divorce and child-custody proceedings in the period before Ms. Kennedy’s death. The body of Ms. Kennedy, 52, was found in a barn on the property. The medical examiner said she died of asphyxiation after hanging herself.