This study was inspired by the observation that foreign financial service firms operating in the City of London do not suffer the liability of foreignness to the extent suggested by theory. To examine the reasons for this departure from theory, the study advances a theoretical framework that distinguishes between three types of advantages that together account for the competitive performance of MNEs relative to that of indigenous firms. Empirical analyses of a sample of 296 foreign financial service firms in the City of London show that in this particular context major sources of competitive performance are the firm-specific advantages and the advantages of multinationality, where British firms may not necessarily possess an advantage over foreign firms. An examination of the validity of the findings, in order to assess the extent to which this situation is unique to the City of London or rather signifies a more general trend that requires theoretical modifications and extensions, is emphasized as a major task for future research. Copyright © 2003 John Wiley & Sons, Ltd.