Financier Derek Quinlan is reported to have found a buyer for his $25m (€18m) Upper East Side townhouse in Manhattan.
The house, which is between New York's Park and Madison avenues, was put on the market in 2008 for $36m.
No details of the price paid have been disclosed but another mansion close by sold for $23m earlier this year.
The sale of the 10,000sq ft property was listed in New York on September 30, according to a report.
Mr Quinlan sold a second Manhattan home in August. The sales come as Mr Quinlan continues to raise money from his international assets. These properties are outside of those that NAMA appointed a receiver to sell.
Mr Quinlan, who moved to Switzerland two years ago, is now based in London and is said to be doing some "asset management" consultancy work for the billionaire Barclay brothers Frederick and David.
Their spokesman said Mr Quinlan had no role in the Maybourne Hotel group the Barclays were trying to wrest control of from Irish developer Paddy McKillen, the biggest shareholder.
The group includes Claridges, the Berkeley and the Connaught hotels in London.
This week, Mr McKillen's lawyers lodged papers in London's High Court to try to block a hostile takeover of the hotels by the Barclays. Mr Quinlan is still the registered owner of 35pc of the hotel group's shares, even though his voting rights are now held by the Barclays, who own 90pc of the company's loans.
Mr McKillen is taking the legal action to "protect his shareholding", he said, and blamed NAMA for "facilitating a hostile takeover" of these trophy assets.
Speaking through a spokeswoman this week, Mr McKillen accused NAMA of behaving like "corporate terrorists" in the way it sold €800m of the hotels' loans to the Barclays.
This deal could help them to squeeze him out of the hotels where he has a 37pc stake. He is now suing the Barclay brothers and companies associated with them to protect his investment.
Mr Quinlan led the audacious €1.2bn bid for the hotels in 2004 but has not been involved with them for the past couple of years.
Mr McKillen was the driving force behind renovating and extending the Connaught hotel and was successful in getting planning permission to carry out a makeover at Claridges and the Berkeley.
He believes NAMA's deal with the Barclays was a "bad one" for taxpayers.