Telstra lodged an application with the ACCC in December 2007 arguing that it should not have to meet the Standard Access Obligation (SAO) for supplying access to its copper network to Optus in any area that falls within 75 metres of an Optus customer connected to a Hybrid Fibre Coaxial network in Sydney, Melbourne and Brisbane.
Should Telstra's application have been approved, Optus would have stood to lose a considerable number of fixed telephone customers in key metropolitan markets.
The Tribunal concluded that such a discriminatory access policy would "be likely to seriously hamper the achievement of long-term dynamic efficiency and sustainable full facilities-based competition."
Forcing Optus to build out extra copper to serve existing customers would be "an inefficient and 'socially wasteful' outcome," the Tribunal said.
The decision was welcomed by ACCC Chairman Graeme Samuel, who has of late pulled no punches in his criticism of Telstra's market behaviour.
"Telstra's exemption application focused too much on one competitor, rather than on benefiting consumers and competition generally," he said.
"The Australian Competition Tribunal's decision affirms that open and equivalent access for all parties is required for effective communications regulation."
The decision is one of several that have gone against Telstra in recent months.
Telstra had previously argued that 371 of its metropolitan exchanges should be exempt from service obligations, as in many cases three to five competing service providers have their own equipment installed within these exchanges.
In this case the ACCC sided with the incumbent carrier, but the application was nonetheless rejected by the Competition Tribunal in January.