Carlson Hotels is planning a $125 million upscale Radisson hotel for the first 18 floors of the Aqua skyscraper downtown.

The hotel, slated to open this fall, would be the first Radisson Blu in the country and is part of the hotel group’s $1.5 billion plan to revitalize the Radisson brand in the United States. The costs are being split 50/50 as part of a joint partnership with Magellan Development Group, the developer of Aqua, the 82-story mixed-use skyscraper known for its swelling wave-like balconies.

Thorsten Kirschke, president of the Americas and chief operating officer for Carlson said the opportunity to develop a hotel at the Aqua building came to the company in late 2008 after a deal to turn 15 floors  into a Fairmont-brand hotel fell through.

Aqua was originally meant to contain condominiums and a hotel. But the economic crisis forced many of those condominium units to become rental units  and stalled the hotel  project.

“It’s through and through a flagship hotel,” Thorsten said of the development planned for Chicago. “We try really to not be in any way cookie cutter. There’s a space for a hotel in today’s world that is not a commodity but speaks through its elegance and individuality with contemporary design.”

Kirschke said the brand’s 200 Radisson Blu hotels are mostly in Europe and can be best described as “upper upscale.” Rooms, he said, are expected to average more than $200 per night. Pierre-Louis Giacotto, a former general manager at the Rosemont Hotel, has been chosen as Radisson Blu hotel’s general manager.

Carlson and Magellan staged a mock-ground breaking by slicing into a 4-foot-tall cake shaped like the Aqua building and presented the Greater Chicago Food Depository with a check for $25,000.

jwernau@tribune.com