Fellow state-owned energy company Tarong Energy Corporation posted a 9.7 per cent decline in net operating profit to $97 million.

Energex, which has owned and operated one of Australia's largest electricity distribution networks for more than 80 years, in recent years has embarked on multi-utility strategy.

This resulted in the acquisition of a south east Queensland gas company in 1998 and the securing of the Victorian Release Gas Program to become the fourth retailer granted the right to sell gas in Victoria.

More recently, Energex strengthened its place in the Victorian market after committing to purchase gas from the new Patricia Baleen field off East Gippsland - the first major offshore source of gas in Victoria for 35 years.