Unbundling and open access regime are two important elements during the implmentation of gas liberalization in US, Europea and Japan, and the proposal of gas liberalization in South Korea and Taiwan. So far, most comtemporary literature mainly focuses on the introduction and analysis of unbundling and open access regime in the individual legal regimes. This article wishes to broaden the research scope of literature by integrating the liberalization regime in the LNG countries into the main stream dicussion of the liberalization in US and Europe.

The purposes of this article are to have an overview of the unbundling and open access regime in US, Europe and LNG countries (Japan, South Korea and Taiwan) and to find out the regulatory patterns. For these purposes, this article will firstly investigate into the unbundling and open access regime in US, Europe and LNG countries. Accordingly, four regulatory patterns are found. They are: (1) the regulatory patterns of unbundling in US, Europe and LNG countries (Part 2); (2) the regulatory patterns of open access regime (Part 3); (3) Overall regulatory patterns of unbundling and open access regime (Part 4); (4) Coherent and incoherent regulatory patterns of unbundling and open access regime across US, Europe and LNG countries (Part 5).