本稿は、会社の倒産局面で株主が会社に対して有する債権について、他の一般債権と異なる取扱いを認めることの根拠およびそのような取扱いを認める必要性を考察するものである。 / 博士(法学) / Doctor of Laws / 同志社大学 / Doshisha University

This thesis addresses risks of multiple recovery, prejudice to legitimate interests of third parties, and inadequate consideration of the applicable law in shareholder claims in investment treaty arbitration. It challenges the application by investment tribunals of two basic premises: i) that shareholders are entitled to claim for damages vis-à-vis measures against the company in which they hold shares and ii) that ‘contract claims’ are to be distinguished from ‘treaty claims’. The central argument is that the failure to recognize substantive overlaps between shareholder treaty claims and contract claims risks more than one recovery, potentially prejudices third parties, and can lead to an incomplete application of the applicable law. The foundations of standing and the cause of action in shareholder treaty claims involve two complementary ideas of independence, i.e., independence of shareholder treaty rights vis-à-vis the local company’s contractual/national law rights and independence of treaty claims vis-à-vis contract claims. However, the substance of shareholder treaty claims, defined as the state measure and particularly the losses involved, is often identical to or at least overlaps considerably with related contract/national law claims. Prevailing ideas on shareholder standing and the cause of action in international investment law have provided useful conceptual tools for jurisdictional determinations. Yet they have not allowed tribunals and the literature to fully consider the implications of shareholder indirect claims. The thesis argues, first, that investment tribunals should acknowledge substantive overlaps between contract and treaty claims. Second, shareholder claims may be inadmissible when such overlap exists and there is a risk of double recovery or prejudice to third parties. Third, the substantive coincidence of treaty and contract claims calls for an integrated approach to the applicable law, where proper weight is given not only to IIA provisions but also to general international law and the national law governing the investment.