(Mark Your Calendars: RealShare Distressed Assets takes place Oct. 4-5 in Grapevine, TX. RealShare New York takes place Oct. 12 at the Marriott Marquis.)

NEW YORK CITY-After acquiring the US office assets of publicly-traded REIT Trizec Properties in 2006 for $9 billion, Brookfield Office Properties Inc.’s joint venture partner, the Blackstone Group, has exercised its call option on 18 of the office properties it manages in the JV. The deal is in exchange for 100% of its interests in the 38-property portfolio of Brookfield-managed assets, SEC filings show. In exercising the call option, Blackstone retired its share of the joint venture debt and assumed the property-specific debt on its managed assets, according to Brookfield.

Under the original JV agreement, Brookfield granted the put/call option on its non-managed properties, with the lion’s share in Southern California and three in New York City. “When the joint venture was originally put together as part of a vehicle to acquire Trizec back in 2006, this was part of that agreement, and just in 2011, this was their opportunity to exercise it,” a spokesman for Brookfield tells GlobeSt.com. “It was something that was always kind of expected.”