XRG, the international energy investment unit of Adnoc, has agreed to acquire Shell’s stake in an Australian natural gas project for $1.5 billion, as the company seeks to diversify its portfolio amid disruption to global energy markets caused by the Iran war. Abu Dhabi-based XRG will buy the stake in Australia's North West Shelf LNG project, marking its first investment in the country's gas sector and opening up greater access to customers in the Asia-Pacific region, the company said on Tuesday.