IEG (formerly Masefield Energy Holdings AG) was created to reflect the diversified international nature of the business moving forward. Masefield has a 20% direct shareholding in IEG. The shareholders interests in IEG and Masefield have a large degree of commonality. IEG subsidiaries include:
 

Nautical Petroleum plc is an independent hydrocarbon exploration and development company listed on the London AIM. The company's mission is to acquire, develop and add value to discovered heavy oil, initially on the United Kingdom Continental Shelf. IEG has a 44% shareholding in Nautical Petroleum.

QFI produces an emulsion fuel as a low cost substitute for conventional heavy fuel oil (HFO) for use in power generation plants and large steam raising or energy consuming industries. IEG has a 59% shareholding in QFI.

Wilton Petroleum Limited is a hydrocarbon exploration and production company whose aim is to develop and produce oil and gas internationally, with particular focus on heavy oil and Africa.