| International energy infrastructure projects are highly involved by national governments, and participants from diverging disciplines and multiple countries, so conflicting logics bring institutional pressures to projects. The mobilization of collective action to respond to institutional pressures is a response strategy that has potential to shape the institutional demands, but its mobilizing structure and enabling conditions is underexplored. To explore how project organizations collectively respond to institutional pressures in international energy infrastructure projects, a case study centered on an international pipeline project was conducted. Four vignettes were developed and compared, each describing an event in this pipeline project about organizational responses to a specific institutional pressure. The results indicate that diverging institutional logics between participants from various countries are the salient institutional pressures in international energy infrastructure projects. Participants from different countries have regulative, normative and culture-cognitive differences. Besides, laws and regulations of the host country may be conflicting with the project time schedule. Project participants from multiple levels are mobilized in collective responses to institutional pressures: the government level, the parent company level, investor level and project level. The organizational mobilization processes include five categories: vertical, horizontal, the hierarchical structure based on the contract, the hierarchical structure based on the parent company, and mobilizing organizations outside the project. Shared identity and accumulation of power are the two conditions of collective responses to the international energy infrastructure conditions. This research contributes to the knowledge of international project management by drawing upon institutional theory and using a strategic perspective to institutional pressures. |