TasPorts has been accused of misusing its market dominance to prevent a commercial operator from competing with its marine pilotage and towage business.
The matter relates to TasPorts' dealings with Western Australian marine services company Engage Marine, which has been trying to expand in Tasmania.
The case is being pursued in the Federal Court by the Australian Competition and Consumer Commission under new "misuse of market power" provisions.
"In short, our case is that TasPorts sought to maintain its monopoly in towage and pilotage in Tasmania, resulting in higher prices and lower quality services," ACCC chair Rod Sims said.
"This is the first case under the amended misuse of market power provision, an important law reform designed to protect the competitive process and help us address the harm that anti-competitive conduct does to consumers and the Australian economy."
TasPorts said it "strenuously denies that it has breached competition law as alleged by the ACCC" and would "vigorously defend" itself.
"The issues raised by the ACCC are complex, based on unique situations; they involve a law that has not yet been tested," TasPorts said in a statement.
Engage Marine has been contacted for comment.
Engage Marine in 2017 won a contract to supply marine services in Tasmanian ports, according to documents lodged in the Federal Court by the ACCC on December 6.
The documents said the contract included towage and pilotage services to Grange Resources at Port Latta, which had been supplied by TasPorts since 2009.
The documents then allege TasPorts imposed a new charge on Grange for Port Latta of around $750,000 a year but offered to reduce it if Grange agreed to a new contract with TasPorts.
It also alleges TasPorts imposed new charges for Engage Marine's tug boats and use of temporary berths and refused to allow Engage Marine to sublet a berth at Devonport off another shipping company.
It also alleges TasPorts "failed or refused" to provide any pilot training to Engage Marine, facilitate the provision of long term berths for their tugs and include the company in the shipping schedule as a towage service provider.
"TasPorts' conduct has prevented or hindered Engage Marine from competing or effectively competing in the relevant markets," the documents said.
"TasPorts' conduct has substantially lessened competition in the relevant markets and denied Grange and other Tasmanian customers the benefits of competition in the supply of marine services, including in relation to the price and quality of those services."
TASPORTS TO COOPERATE
TasPorts is owned by the Tasmanian government and operates every port in the state except for Port Latta.
The business said it had a range of "important responsibilities regarding the operation of Tasmanian ports".
"TasPorts' principal objectives are to facilitate trade for the benefit of Tasmania and to operate its activities in accordance with sound commercial practice," TasPorts said.
"TasPorts plays a critical role in ensuring marine safety and environmental management in Tasmanian waters. TasPorts takes all its legal and regulatory responsibilities and obligations very seriously.
"TasPorts has cooperated with the ACCC in its investigation. TasPorts strenuously denies that it has breached competition law as alleged by the ACCC. TasPorts will vigorously defend the ACCC's allegations".