Interlibrary loans in the Federal Republic of Germany are facilitated by applying techniques of data processing and computer output microfilm (COM) to the union catalogs of the national library system. The German library system consists of two national libraries, four central specialized libraries of technology, medicine, agriculture, and economics, and approximately 20 regional libraries operating in decentralized cooperative networks. The national library in Berlin prepares COM union catalogs of the national serials database at 6-month intervals for use by the regional libraries, each of which prepares magnetic tape information on their new accessions for the national library. The COM union catalog processing originated as and still is an offline process; however, the processing and management of bibliographic data to be practical in the future must be developed as an online system. A national program has been devised to provide a computerized online system within the regional networks of libraries in the early 1980s. The library centers thus equipped will fulfill the multiple functions of accelerated technical processing of books and periodicals, production of COM union catalogs and an online interlibrary loan capability, and creation of a national subject information system. (RAA)