Triple Net Properties LLC, on behalf of NNN Congress Center LLC, has purchased the 524,784 sq. ft. Congress Center for $136.1 million. The office building, located in Chicago’s West Loop submarket, will serve as Triple Net’s fifth regional office. Other major tenants include the U.S. Department of Treasury, North American Co. for Life and Health, GE Reinsurance Corp. and the U.S. Secret Service.

The Santa Ana, Calif.-based firm, which manages more than 9 million sq. ft. of commercial properties, is currently buying properties throughout the Western U.S., Florida, Illinois, Tennessee, Texas and Hawaii. The company’s other recent transactions include the purchase of Parkwood I & II in The Woodlands, Texas, for $20.4 million. Major tenants of the 196,128 sq. ft. office building are MGL Consulting Group and Entergy Enterprises.