Fire chiefs from two services in Sussex are examining ways of working closer together.
East and West Sussex fire services said they were exploring options for "greater collaboration" and no options had been ruled out.
The aim is to make savings in management costs and back office functions.
East Sussex Fire Authority and West Sussex County Council (WSCC) will make a final decision in March.
Councillor Ted Kemble, who chairs East Sussex Fire Authority, said: "Working closer together may enable significant savings."
Councillor Peter Evans, cabinet member for public protection at WSCC, described the plans as "important and historic".