Because of data ownership questions raised by the interchange and sharing of machine readable bibliographic data, this paper was prepared for the Bibliographic and Communications Network Committee of the National Library Advisory Board. Background information and definitions are followed by a review of the legal aspects relating to property and contract law. The treatment of ownership of machine-readable bibliographic data and databases in 22 agreements is then examined, including library processing center agreements, information retrieval center agreements, and bilateral agreements for the international exchange of MARC records. Relevant ongoing and recent work is surveyed concerning bibliographic records in machine-readable form and copyright law. Outstanding issues in network agreements related to data ownership are reviewed and considered in host/host user agreements and database supplier/host organization agreements. Copyright law revision issues are also noted. Twenty-six references are listed, and appendices provide the recommended text for a bilateral agreement for the international exchange of MARC records via tape format between national bibliographic agencies, and EURONET guidelines for cooperation between database suppliers and host organizations. (LMM)