The long-stalled Harlem Park site at 1800 Park Ave. is being resurrected as a residential building with a big affordable component by Ian Bruce Eichner of Continuum Co.

Vornado Realty Trust earlier this week announced the $65 million sale of the site at the southwest corner of East 125th Street but didn’t reveal the name of the buyer.

According to several sources, Eichner is planning an 80/20 residential building of 596,000 square feet. It would include street retail, a garage and roughly 600 apartments, with at least 200 affordable units.

Among Eichner’s developments are CitySpire on West 56th Street; 180 Montague St. in Brooklyn; 1540 Broadway in Times Square; and the Cosmopolitan in Las Vegas.

He is as well known for developing high-profile projects as he is for losing them — including 1540 Broadway and the Cosmopolitan — to his lenders.

While Eichner’s source of financing could not be learned, the city is encouraging more affordable housing, so it would not be a surprise if low-interest financing and bonding come into play.

Eichner did not return a call or e-mail for comment.

In 2004, financing was approved for a $200 million Courtyard Marriott and office building to be developed by Michael Caridi and Raymond P. Caldiero, chairman of the Sequoia Group.

Without commercial office tenants, the site was acquired by Vornado in 2007. It planned a 600,000- square-foot office building with 72,000 feet of retail, but that also never came out of the ground.

In 2010, Vornado bought out its partners, California Urban Investment Partners — a joint venture among the California Public Employees’ Retirement System, Earvin “Magic” Johnson’s company and MacFarlane Partners — for $11.85 million.

The site wraps the entire eastern end of the block between Madison and Park and East 125th and 124th streets.