This thesis report aims at addressing transactional issues raised by the undertaking of eco-industrial parks (EIP) development. The economics of eco-industrial synergies (resource "flow" substitution and infrastructure/service "capacity" sharing) is investigated so as to complement existing engineering-oriented approaches. A focus is made on industrial stakeholders' interplay in industrial symbiosis (IS) and their strategic decisionmaking in terms of investment and contracting practices. First, a survey of practices actually observed in EIPs in function is conducted through a literature review. A taxonomy of eco-industrial synergies is thus proposed and an IS implementation process representation is derived. Then we conduct a case study on the GreenValley eco-industrial park (France) Then, from economic arguments (transaction costs) we advocate the use of long term contracting in organizing IS related transactions. Following this, a contract design framework including specific provisions (tarification, penalties, warranties) is proposed in order to perform pricing of flows exchanges and risk sharing. In a last part, investment decisions in shared capacities is studied using economic modelling both in cooperative and non-cooperative game setting. Key economic parameters (size, back-up costs, scaling factor) and behavioral decisions (investment, commitment) are described and uncertainty is treated in two different approaches.