The council-owned office block on Grantham Street in Lincoln, has been sold to a local business.
The three-storey office block was no longer required by Lincolnshire County Council and has been vacated.
Cllr Rob Gibson, executive councillor for property at the county council, said: "This is a great result for the council – saving us money every year on the upkeep of the building and generating £900,000 to invest in other projects.
“It’s also enabling a local business to expand and gives the building a new lease of life. This is really important to us when we sell any of our properties – we’re looking to get the best use of the building - supporting the economy or the local community wherever possible.”
The sale of the building is part of the council’s property rationalisation programme which sets out to increase overall efficiencies and help the council deliver services.
Cllr Gibson added, “The main objectives are to reduce running costs, generate capital receipts and reduce under-utilised properties and land. Helping a local businesses at the same time is the cherry on top!”