During a resale, a lease can be re-assigned from one franchisee to another to save the time and expense of developing a new lease agreement. This is decided by the landlord and commonly agreed upon by both the franchisor and the franchisee.
In some cases the lessor will require a new lease. Usually this occurs because the original lease has only a short time remaining before expiration. In other cases the lessor might believe a new lease agreement would provide more security or rental income than the prior franchisee provided.