A spokeswoman for Norfolk Southern declined to comment, citing policy on real estate matters.
CIM Group founder Richard Ressler did not immediately return messages seeking comment. Ressler is the brother of Hawks lead owner Tony Ressler.
Attempts to contact a Hawks representative were not immediately successful.
Atlanta Mayor Kasim Reed has said a deal to overhaul Philips Arena would lead to downtown redevelopment.
Norfolk Southern trains travels under the newly opened Mitchell Street Bridge in downtown Atlanta Thursday morning in Atlanta, Ga., August 23, 2012. The former Norfolk Southern office building downtown is visible to the right. AJC File Photo
CIM’s plans for the massive building aren’t clear, but the building could be prime for a Ponce City Market-style rehab into loft office space, retail and residences.
The old Norfolk Southern building is seen as an anchor for redevelopment of south downtown.
The railroad company quietly solicited requests for proposals for the building, as well as adjacent land and two brick buildings south of the main complex across Peters Street.
A Norfolk Southern train travels south close to the Mitchell Street bridge in the Gulch Tuesday afternoon in Atlanta, Ga., May 28, 2013. The Norfolk-Southern route runs north-south through downtown beneath the Georgia World Congress Center (GWCC), through the Gulch, and then onward to parallel MARTA’s Red/Gold lines south of downtown. AJC File Photo
German developer Newport US RE is buying up blocks of historic buildings and land downtown, and it is negotiating to purchase the nearby former C&S Bank headquarters building on Mitchell Street. The firm at one point also had interest in the Norfolk Southern property.
A South Carolina group, meanwhile, closed in March on its purchase of Underground Atlanta with plans to convert the struggling mall into a mix of retail and apartments.
Rendering of the refurbished interior of Philips Arena provided by the Atlanta Hawks The transformation will be completed by the start of 2018-2019 season, coinciding with the Hawks’ 50th Anniversary in Atlanta. The Hawks will play next season at Philips.
The Hawks and the city of Atlanta recently completed a deal for a $192.5 million overhaul of Philips Arena, including $142.5 million in public financing.
In March 2016, amid arena negotiations, the AJC first reported the team's discussions with the city about an entertainment district and mixed-use development near Philips. In June, the AJC first reported the Hawks and their partners were in advanced discussions with key land owners, including the city and Norfolk Southern, to acquire or take on development rights to parcels in and around the Gulch.
But at the time, it wasn’t clear which parcels the partners had in their sights.