Michael Silberberg with New York-based Berkley Properties has entered into a purchase and sale agreement with the Prime Group REIT to buy the 770,000-square-foot 180 N. LaSalle, which the trust says is about 75% occupied, with major tenants that include Accenture, Career Builder and Performics Inc. According to a REIT statement, the trust will receive net proceeds of about $12.5 million from the sale, which is expected to close by June. The trust said Silberberg has provided $4 million in an earnest deposit for the purchase. Neither Silberberg nor trust executives returned calls for comment on this story.

While it's true that $72 million is much less than the previous offers in 2009 from Winthrop Realty Trust and Younan Investment Properties LP, at up to $116 million, those two deals did not make it through financing approval. Prime Group reportedly bought the property for less than $60 million in 1998, though the trust did pour more than $20 million of renovations into the tower.

As for the defaults, Prime said in the statement that two of its subsidiaries, each of which owns separate portions of the 844,000-square-foot Continental Towers complex on West Golf Road, are in default under their respective first mortgage loans encumbering the complex. Continental Towers Associates III LLC, which is the owner of the 281,528-square-foot Tower II portion, is in default under its loan "because the cash flow from the CTA III property is not sufficient to pay the required escrows and debt service payments on the CTA III loan," Prime Group said in the statement. The CTA III loan is for $41.4 million. Continental Towers LLC, which owns the other two buildings with a $73.6 million loan, also is in default "because it is cross-defaulted with the CTA III loan," the REIT said.