ABSTRACT
This chapter investigates the general principles that have emerged from the case law regarding the expropriation of contractual rights and analyses the particularities and circumstances surrounding the expropriation claims. International law has recognised that not only tangible property but also contractual rights may be expropriated by states and that expropriation claims may be pursued in arbitration proceedings as provided in investment treaties. The starting point for any review of whether contractual rights are protected from expropriation depends upon the wording and definitions contained in the relevant investment treaty. The tribunal in Siemens v Argentina reviewed the relevant case law and concluded that: for the State to incur international responsibility it must act as such, it must use its public authority. Claims relating to intangible property, including contractual rights, are increasingly becoming the more common basis of expropriation claims under investment treaty law.
