Willis Tower in Chicago sold for $1.3 billion

CHICAGO, March 16 (UPI) -- Private equity real estate investor Blackstone Group on Monday announced it is buying Chicago's iconic Willis Tower -- formerly Sears Tower -- for $1.3 billion.

That's the largest amount ever paid for a U.S. office outside of New York, the Wall Street Journal reported.

The most ever paid for a building in Chicago was $850 million last year for the sale of 300 N. LaSalle, a 60-story mixed use building.

"We are bullish on Chicago as companies expand within and move into the city and look for first-class office space," Jacob Werner, a managing director for Blackstone, said in a statement. "Moreover, we see great potential in further improving both the building's retail operations and the tourist experience for one of the most popular destinations for visitors to Chicago."

Blackstone plans to upgrade the 103rd-floor Skydeck with the hopes of bringing in more tourist dollars. The Skydeck brought in about $25 million in 2014. It also intends to invest in the retail portion of the building.

Willis Tower was built in 1973 and stands 108 stories or 1,451 feet tall, making it the second-tallest building in the United States. It was initially called Sears Tower -- a name still commonly used -- but it was renamed in 2009 when Willis Group leased the naming rights.