This is the first electricity regulatory report published by the AER following two previous reports issued by the Australian Competition and Consumer Commission. This report covers the performance of eight transmission network service providers for the 2004/05 regulatory year: ElectraNet SA, EnergyAustralia, Murraylink Transmission Company (Murraylink), Powerlink, SPI PowerNet (now part of the SP AusNet group), Transend, TransGrid and VENCorp.