The Skyline is Falling in Chicago...

in terms of office rates.

Jones Lang LaSalle Inc. is out with its 2010 Chicago Skyline Review. It covers the 53 skyscrapers it considers as the core of the downtown market and shows floor by floor where the vacancies are, reports Crain's.

Overall, the 53 buildings Jones Lang highlights report an average vacancy rate of 14.9 percent, five percentage points higher than a year ago.

Rents are down about 25 percent from a year ago, once landlord freebies are considered, says Steve Smith, managing director at Jones Lang who advises landlords, according to Crain's.

In 2010 and 2011, the downtown market has 25 properties with maturing debt worth $2.4 billion, Jones Lang said. Some of those owners could be sweating, as the value of their buildings is down 25 percent to 40 percent from 2006.

Bruce Miller, managing director for capital markets at Jones Lang, thinks most lenders will extend terms rather than foreclose.