NEW YORK CITY — Ariel Property Advisors has arranged the sale of a two-building multifamily portfolio located at 517 W. 180th St. and 570 W. 182nd St. in the Washington Heights neighborhood of Manhattan. A private investor acquired the portfolio for $15.8 million. Totaling 37,305 square feet, the portfolio features 51 residential units in one-, two-, three- and five-bedroom layouts. Thirty-nine of the units are rent stabilized and 12 are free-market apartments. Michael Tortorici, Victor Sozio, Matthew Gillis and Shimon Shkury of Ariel Property Advisors represented the seller, a private investor, and the buyer in the deal.