The real estate firm also spent an estimated $13 million on buildings at 11130 and 11166 Main St. in Fairfax City, VA. Those buildings, totaling 100,111 square feet, had been owned by Mass Mutual. Those purchases followed the June 2000 acquisition of an office building at Westwood Center in Vienna, Va.The six buildings represent a nearly $51 million investment, and Guardian is looking for more investments in what it is calling a $100 million "shopping spree."

"We are looking for properties in the Mid-Atlantic region that fit the profile that we have: which includes properties that need a certain amount of tender loving care, repositioning and capital improvements," explained Tony LaBarbera, managing director of Guardian Realty Investors LLC.

Guardian wants to acquire 40,000 to 250,000 square-foot office buildings after securing financing last year from Charlesbank, the real estate advisor to Harvard Endowment. The company aims to close deals in fewer than 60 days. Guardian Realty's real estate portfolio includes more than 1.5 million square feet with a value of more than $250 million.