Australia's mobile phone industry could be set for a shake-up with the competition regulator to rule on Friday on what operators can charge rivals to access their networks.
A move by the Australian Competition and Consumer Commission to regulate mobile roaming charges could deliver a major blow for Australia's biggest telecommunications companies, Telstra and Optus.
The two telcos - who between them have about 27 million mobile subscriptions - have opposed any controls on the charges, arguing that competition is healthy, and regulation will hurt rural network investment.
Analysts say Telstra would be the biggest loser should the ACCC regulate roaming, because it would increase competition over the short term and drive down prices.
Its profit and dividends would also come under pressure.
Telstra has the greatest regional coverage after investing billions in mobile infrastructure and says regulation would not address coverage issues but would stall investment and leave regions worse off.
The company blames any lack of competition on competitors' failure to invest in regional areas.
Vodafone - which has 5.5 million customers but a limited presence in the bush - has been pushing for regulation and blames Telstra's dominance for the lack of competition.
It says Telstra's market share in regional areas ranges from "market dominance to absolute monopoly".
In recent months, Telstra chief executive Andy Penn and Vodafone boss Inaki Berroeta have travelled the country lobbying rural communities for support.
Prices for roaming between domestic networks - the function that allows users of Vodafone, for example, to access Telstra's service in far-flung rural areas - are currently unregulated.
The ACCC has been investigating domestic mobile roaming for the past eight months. It is its third review in 19 years.
The inquiry was launched on September 5, with the ACCC saying that access to a roaming service would enable mobile companies to provide coverage for customers in areas where they don't have their own network.
"Consumers are increasingly relying on mobile services and the issue of coverage and a lack of choice in some regional areas is a particular issue that has been raised by a number of groups," ACCC chairman Rod Sims said at the time.
Mr Sims is expected to hold a media teleconference on Friday morning to discuss the ACCC's decision.
