Japanese equipment manufacturer OKI has signed a contract with Mitsubishi Heavy Industries to supply towed passive sonar systems and related equipment for Australia's new frigate programme.
The agreement covers equipment for the first three vessels in a planned fleet of 11 frigates being acquired by the Australian Government.
In August 2025, the Australian Government selected Japan's upgraded 06FFM frigate, an enhanced version of the Mogami-class design, for the country's general purpose frigate programme.
The vessels will be equipped with OKI's towed passive sonar system, which detects underwater targets by receiving acoustic signals from sensors towed behind the ship.
According to the company, the contract represents its first overseas transfer of defence equipment. OKI has primarily supplied acoustic sensors and sonar systems to the Japan Maritime Self-Defence Force.
The company also said that it intends to expand production capacity and strengthen overhaul capabilities to meet increasing demand in the defence and ocean sectors, which have been identified as priority areas under the Japanese Government's growth strategy.