One of the largest real-estate sales in Kirkland’s history, Kilroy Realty purchased the Plaza at Yarrow Bay for $100.2 million on Thursday.

HAL Real Estate Investments of Seattle sold the four-building office complex at $363 per square foot after 10 years of ownership, according to King County tax records.

The 276,000-square-foot complex, which comprises four buildings ranging in height from three to five stories, was built in 1987 and expanded in 1994. It still has room for another 80,000 square feet of development.

The site is primarily located at the intersection of Lake Washington Boulevard N.E. and State Route 520, by the City of Bellevue border in the Lake View neighborhood. Business occupants include Allyis, Directors Mortgage Inc., Hodgson/Meyers Creative Marketing, Advaiya, Inrix, Ciber and the University of Washington’s Foster School of Business, among others. The buildings have a combined vacancy rate of between 8-14 percent.

HAL recently updated the lobby, cafe and athletic facilities in the complex, according to the Puget Sound Business Journal.

Los Angeles- based Kilroy, which is a real-estate investment trust, is a publicly traded company on the New York Stock Exchange. According to the company’s Web site (www.kilroyrealty.com) it has also made seven other major acquisitions recently, all in California. Kilroy owns 10.4 million square feet of office space and 3.6 million square feet of other real estate on the West Coast. The company also purchased the 122,000-square-foot Overlake Office Center in Redmond in October of 2010 for $46 million, which is primarily occupied by Microsoft Corp.

The sale of the Plaza at Yarrow Bay also ranks as the largest in King County this year. And there were only four real-estate sales of more than $100 million last year in the county.