Senior Housing Properties Trust (NYSE: SNH) recently announced that it will acquire 27 medical office properties that includes 2.8 million square feet in 12 states for $470 million. SNH purchased the properties from CommonWealth REIT (NYSE: CWH) where SNH was a wholly owned subsidiary of CWH until it was spun out to CWH shareholders in 1999. As part of the spinout, SNH retained the right of first refusal on the purchase of certain properties and the properties in the transaction were part of those rights. CWH and SNH are both managed by Reit Management & Research LLC ("RMR") and special committees and counsel were used to ensure that the transaction was structured properly given the common management platform. Senior Housing Properties Trust plans on using cash on hand and its revolving bank credit facility to purchase the 27 properties and expects all the property transactions will close by June 30, 2011.