The suburban properties in the portfolio are expected to sell between $200 per sf and $225 per sf and the Chicago properties are expected to sell between $300 per sf and $330 per sf, Postweiler tells GlobeSt.com. "People are expecting that the sales prices will be at the upper end of ranges that have already been established," he says.

Bidders could "include any profile you want to include" such as investment funds, pension funds and private equity groups, Postweiler says. Executive vice president for Studley John Goodman, told GlobeSt.com earlier this month "From what I understand, there are about five or six major institutional owners of real estate who are looking at [the Civic Opera House] building as part of their Chicago portfolio."

The sale of the portfolio has already had an effect on the Chicago commercial real estate market. Some property owners that were thinking of selling have held off for this portfolio to be sold, according to Postweiler. "Because of its size, most owners especially with smaller properties were trying to evaluate when it would come and if marketing their building would be impacted by this portfolio being on the market," he says.

For those that were waiting for the Blackstone portfolio to be sold, "It has been so long of a period now, they have blown through some of their own deadlines that they set." The sale of the portfolio has been talked about for months, says Postweiler who did not know why exactly the sale had been delayed. There has been speculation that Blackstone was trying to finish a few large lease transactions at the Mercantile Exchange and discussions with joint venture partners for a few of the buildings.