The city’s announcement that it would move migrants out of the Roosevelt Hotel by June made the precious East Midtown site Topic No.1 among commercial developers.

The property’s owner, the Pakistan government’s Pakistan International Airlines (PIA), wants to sell it for what sources said could be $1 billion.

A developer could tear down the antiquated hotel to build a skyscraper of up to 1.8 million square feet on the roughly 42,000 square-foot parcel, sources said. A project so large would need to exploit recent area rezoning which raised maximum FAR (floor-to-area ratio) from 15 to 30, available only if a developer provided transit and public-space improvements and amenities subject to city and MTA review.

PIA’s sale agent, JLL, has yet to issue a formal solicitation, which will likely happen in the spring. However, market sources told Realty Check that “informal conversations of interest” have taken place with developers including Tishman Speyer, Related Companies, SL Green and Vornado.