The tasks of creation, management, and maintenance of multilingual subject authority files require significant resources, and are therefore best carried out in cooperation. Four national libraries in Europe (the Swiss National Library, la Bibliotheque de France, Die Deutsche Bibliothek, and the British Library) have worked together on a feasibility study which looked into linking existing subject authority files in three different subject heading languages (SHLs) to offer multilingual subject access to their files. The aim of the study was to establish equivalents (or best matches) among headings in French, German, and English in comparing both headings from selected subject areas and the indexing of publications. Its four key elements were: (1) to establish a methodology for the selection and linking of headings; (2) to link headings and analyze the results in the selected subject areas of sports and theater; (3) to see the practical applications of these linked headings by indexing 40 titles from the field of theater using each language being studied and comparing the results; and (4) to compare the indexing of titles in other subject fields outside the linking study itself for which indexing was available in each of the SHLs. This paper describes the work carried out so far and explains plans for the future. (Contains 11 endnotes.) (MES)