The study of multinational enterprises (MNE) responses to multiple and contradicting institutional prescriptions has traditionally focused on country-level differences. As the literature acknowledges the strategic impact of multi-level institutional processes (e.g. at the city level), however, analysis of MNEs institutional strategies needs to apply more fine-grained, field-oriented perspectives. Modeling the incorporation of such perspectives, this doctoral thesis explores a comparative case study of two MNE subsidiaries providing car-sharing services in the city-level environments of London (Zipcar) and San Francisco (Audi on demand). The primary case-study data consist of 38 semi-structured interviews with MNE subunit executives, MNE headquarter representatives, city authorities, competitors, and other field actors. A triangulation of 33 industry and governmental publications, available press articles, and the findings of an in-depth focus group enrich the data. First, the analysis depicts the complexity of the organizational field of Urban Mobility and the inherent interplay of various institutional audiences on different levels: MNE headquarter and subunit, nation and city as well as the respective normative, cultural-cognitive, and regulative demands. Moreover, it assesses the strength of institutional actors ties, coupling, and dependencies, thereby addressing the exploratory question: why and how do MNE subunits cope with multi-level institutional processes? Guided by previous theorizing on organizational identity in Organizational Studies (OS) and International Business (IB) research, the analysis reveals that distinct configurations of organizational identity-based enablers and mechanisms define the typology of MNE subunits pro-active institutional strategies. The enablers consist of intraorganizational member identity alignment, describing the congruence of values and goals withinorganizations; field position, delineating the organizations degree of embeddedness; status, defining external image and stakeholder expectations; and perceived power, determining the subunits perceived resource availability compared to other actors. Leveraging the mechanisms of critical self-reflexivity, coherent storytelling, and capability to mobilize others, MNE subunits seem to develop multiple identity configurations. These configurations lead in turn to various institutional responses, i.e. innovation, arbitrage, circumvention, or acquiescence. By emphasizing and outlining the importance of field-level organizational identity as opposed to country-level foreignness, the typology this thesis develops contributes to an institutional reorientation of IB research on multi-level institutional perspectives and strategy formulation, both in academia andpractice.