Two weeks after announcing its plan to acquire seven office buildings in Southern California and Arizona, Pacific Office Properties Trust has closed on the purchase of four properties in San Diego and Phoenix. The REIT bought the assets, which total 275,000 square feet, from The Shidler Group.The San Diego Portfolio, located in the submarkets of Carlsbad and Torrey Hills, consists of an aggregate 54,000 square feet in three structures of Class A and Class B+ status. Pacific Office has a 32 percent ownership interest in the properties, leaving its institutional co-investment partner with the remaining stake. Pacific Office also snapped up Black Canyon Corporate Center, a 220,200-square-foot property in Phoenix’s Deer Valley submarket. The company’s interest in the property is 17.5 percent, and the institutional co-investor owns the remaining interest.As part of terms defined by recent formation transactions with Shidler, Pacific Office has the option to buy 18 office structures from Shidler. Pacific Office expects to close on the acquisition of the remaining three buildings in the previously announced seven-property purchase in June.