GFI then joined with Savanna Partners to convert those floors.
Chris Schlank, an owner, said he had set no asking price for the property, which his company, Savanna Partners, bought through a foreclosure in 1997 for $6 million.
Under a $100 million renovation, Mr. Gross, with Savanna Partners, will convert floors 14 to 23 in the old buildings into a hotel with up to 325 rooms.
Philippe Weissberg of Savanna Partners said the market also supports the Towers at Central Park West project.
The recent actions make it likely that Savanna Partners, which owns the site, will soon sell it to a developer who would build the apartment complex.
He is also redeveloping the former Towers Nursing Home on Central Park West into luxury apartments and "assisted living" units, a $70 million project with Savanna Partners.
Mr. Schlank, 29, is a partner in Savanna Partners, a real estate development firm in New York.
The Peninsula complex itself has been given a $100 million upgrade by Savanna Partners.
One of the buildings, 141 Fifth Avenue, at 21st Street, is a magnificent old dowager in the throes of being renovated by Savanna Partners.
Savanna Partners spent $4.5 million to buy the smaller site, a 600,000-square-foot, two-building complex that was renamed the Ulster County Technology Center.
