Tangguh is being developed at a cost of US$3 billion by British Petroleum and is located in western Irian Jaya. LNG production is expected to reach about 7 million tonnes of per annum but the field will not be ready until the summer of 2007. Mitsui's target market is the Asia-Pacific market, which includes Japan, the US, China and South Korea.

BP is the largest stakeholder (37.2%) with a Mitsubishi Corp and Index Corp joint venture holding 16.3%, CNOOC Ltd owning 12.5% and Nippon Oil Corp holding on to 12.2% share. Once ratified, Mitsui and the other Japanese companies will hold a majority share - making Tangguh the first major natural gas development scheme under Japanese control.