Various reports put Blackstone's IPO at 10% of the company's full worth, or roughly $4 billion. A spokesperson for Blackstone declined to comment on the amount.

Morgan Stanley & Co. Inc. and Citigroup Global Markets Inc. are the global coordinators and underwriters of the transaction. Additionally, Merrill Lynch, Pierce, Fenner & Smith Inc., Credit Suisse Securities LLC, Lehman Brothers Inc. and Deutsche Bank Securities Inc. will be the joint book-running managers.

It's ironic that Blackstone has been involved in a number of public-to-private mergers in the recent past. The firm took the Chicago-based Equity Office Properties Trust private at the beginning of February. The $39 billion Blackstone paid for EOP initially gave it 580 buildings for a total of 108.6 million sf. The firm then launched into a series of big-ticket property flips, including Maguire's nearly $3-billion purchase of certain Southern California holdings.

In October 2006, Blackstone, with the help of New York City-based Brookfield Properties Corp., took Trizec Properties Inc. and Trizec Canada Inc. in a $9-billion deal. The buy-out of Trizec added 48 office properties totaling 26 million sf to Blackstone's and Brookfield's portfolio.

In August, an affiliate of Blackstone purchased Cendant Corp.'s Travelport for $4.3 billion.

In July, Blackstone purchased CarrAmerica Realty Corp. for $5.6 billion, taking 287 office properties totaling 26.4 million sf in 12 markets.

In May, Alcor Acquisition, a Blackstone affiliate, completed its acquisition of MeriStar Hospitality Corp. The $2.6-billion deal brought with it 47 hotels and more than 14,400 keys.