Cogdell Spencer on Friday spent $28.6 million to buy the Healthpark Medical Office Building in Chattanooga, Tenn., and the Peerless Medical Center in Cleveland, Tenn. The company financed the deal in part with $16.2 million in money borrowed at 5.68 percent interest.

Most of Cogdell Spencer's $55.8 million in revenue last year came from collecting rent from tenants -- mainly doctors with medical practices -- on its portfolio of office properties, which currently totals 57 buildings worth $430 million.

The Healthpark Medical Office was built in 2004 and its tenants include the Galen Medical Group and an MRI/Imaging facility for Erlanger Health System. Peerless Crossing Medical Center was built last year and is leased by Peerless Medical Associates, a medical practice with multiple specialties.