Chicago's third largest skyscraper has been sold for a huge price of $712 million. The owner, Piedmont Office Realty Office Trust, announced on Tuesday that the Aon Center has been sold to 601W Companies. The company is a private real estate investment company headed by New York real estate investor Mark Karasick.

According to a report by Chicago Real Estate Daily, the tower's price equates to $260 per square foot, leading up to a sum that is remarkably higher than $650 million, its earlier estimated range. Piedmont hired Jones Lang LaSalle Managing Director Bruce Miller and Senior Vice President Nooshin Felsenthal to sell it earlier this year.

The price blew up to $712 million, just a week after news broke out that the newly-merged Kraft Heinz had signed a 170,000-square-foot headquarters. The deal includes the tower overlooking Millennium Park.

The 43-year-old Aon Center is a 2.7 million-square-foot tall building located at 200 E. Randolph Street. It is reportedly Chicago's third largest skyscraper. The building is 86 percent leased, Piedmont said.

"The successful sale of Aon Center will be the culmination of Piedmont's long-term strategy of transforming the asset into one of Chicago's most prestigious office towers," Piedmont President and CEO Donald Miller said in a statement quoted by the Chicago Real Estate Daily.

According to Chicago Curbed, it was also expected that the Aon Center could be the third Chicago skyscraper to accommodate an observation deck. It is an attraction known to generate up to $30 million annually.

Chicago Curbed added that there is still no update on whether or not the Aon Center's new owners plan to actually build an observatory in the building. In any case, this observatory would be more convenient for tourists to access, versus the observatories at Hancock Center and Willis Tower.

Other than the Aon Center, New York's Blackstone Group has also sold its $1.3 billion tower, which was reportedly the tallest tower in New York.