CHICAGOMark Karasick with 601 W Cos. and Michael Silberberg with Berkley Properties are spending more than $100 million to take a controlling interest in the Prudential Plaza Office Towers here, through a partnership with current owner and operator BentleyForbes Holdings LLC.

The 1950s-era towers take up a full city block overlooking North Michigan Avenue at its intersection with East Randolph Street. Occupying the center point between Illinois Center, the Loop Business District and Grant Park, the Prudential Plaza complex features approximately 2.2 million sq. ft. of Class A office space in two distinctive towers, of 41 and 64 stories. Most of the current vacancy is in the One Prudential Tower. The complex also includes 90,000 sq. ft. of retail.

According to a statement by the companies, the new partners have immediate plans to move forward with a significant asset improvement program, including redevelopment of the property’s retail concourse and common areas, along with significant reserves for leasing commissions, marketing and future tenant improvements. The owners and BentleyForbes reportedly have restructured about $470 million of debt on the property.