The connecting factors of market infrastructures. Today, market infrastructures are systems that have in common, on the one hand, that they are made up of a legal element, the rules of the system, and a material element, the computer system, and on the other hand, that they are managed by an infrastructure manager. For a long time, these different aspects were confused. The contemporary connecting factor of market infrastructures requires a study of the history of the French organisation of financial markets, as well as the European institutional context in which it is embedded today.

At first sight, the contemporary connecting factor of infrastructure managers is not very original: like legal persons under private law, these managers are connected to the legal system of their registered office. However, their uniqueness becomes apparent once it is observed that the registered office in question is their real seat, and that the law of the seat has a particularly broad scope, applying to corporate, prudential and insolvency legislation. This correlation seems to give an additional dimension to the ‘universal law of private international law’, according to which ‘the more liberal the connecting factor, the more the field of the designated law narrows or competes with the attempts to apply third party laws’. In fact, in the same way, the less liberal the connecting factor, the more the field of the conflict rule expands, making the criterion used the preferred instrument for deploying the legislative policy of the legal system designated by the conflict rule.