Unum will demolish the old EPB building at Sixth and Market streets.
Unum will retain the property for possible future expansion in the long term, though there are no immediate plans for such expansion, officials said.
Mary Clarke Guenther, Unum spokesperson, said, "Although we had been working for some time with the city and the RiverCity Company in search of alternatives, no suitable alternatives were available.
"The building is not currently usable for office purposes, and the costs of renovating the property are prohibitive. Rather than allow the property to deteriorate further, the company intends to remove the buildings from this block of Market Street.
"This includes the buildings formally occupied by EPB and the Huckabee Bonding Company."
She said the first phase of this process is the hazardous material abatement which will begin as early as next week and is expected to take up to three months to complete.
The second phase is the removal of the buildings, and this demolition will take up to a year to complete.
Upon completion of the demolition, Unum will use this property for surface parking and will work with the city on the parking design and streetscaping, Ms. Guenther said.