IEA owns three peaking power stations totalling 100 megawatt capacity, two in South Australia and one in NSW, and is building another station in South Australia.
Most of the company's energy operations are in New Zealand and Australia, but it has also extensive transport assets here and in Europe.
The company owns Wellington Airport in New Zealand and has airports in Glasgow and Kent. Infratil's public transport services are in Auckland and Wellington.
Its first investment was a minority stake in TrustPower. It expanded into airport ownership in 1998 when it bought a 66 per cent holding in Wellington Airport.
In November 2005, Infratil purchased bus and ferry business Stagecoach NZ for $250.5 million and in 2006 it bought Wellington bus company Mana Coach Services.
Infratil's NZ Bus is now New Zealand's largest public transport operator with bus services in the Auckland and Wellington regions.
In 2007 the company was named Deloitte/Management Magazine Company of the Year.
In March 2010 Infratil joined with the NZ Superannuation Fund to acquire Shell's retail outlets - which it has rebranded as Z - and its interest in NZ Refining.