An improvement in or relating to a method of conducting real estate sale and financing transaction and a computer system to implement it. The method comprises of a tripartite agreement between Landlord, Tenant-cum-Purchaser and Lender; wherein, Landlord provides possession of real estate without transferring ownership title of said real estate property; Lender agrees to collect loan installments firstly from Tenant-cum-Purchaser and in case of default in payment by Tenant-cum-Purchaser, from Landlord; Lender shall have charge on said real estate property for its unpaid dues; and On successful completion of said agreement, Tenant- cum-Purchaser shall be owner in possession of said real estate property forever. Lender may opt for transfer of risks and benefits from said real estate financing arrangement through securitized investment instruments and formation of an internet based trading platform for such securitized investment instruments and real estate price indexes.