Firmus commits USD 300M to SUBCO's APX East cable for Australia-US AI connectivity

Firmus Technologies has agreed to invest approximately USD 300 million in SUBCO's planned APX East submarine cable system, securing up to 150 terabits per second of dedicated capacity between Australia and the United States for a 25-year term. The agreement positions Firmus as the cornerstone customer of APX East, a direct Australia-US system that SUBCO is developing with a target ready-for-service date in the fourth quarter of 2028.

The investment underscores a broader shift in the data centre and AI infrastructure industry, where securing long-haul connectivity is becoming as critical as building compute capacity itself. For Firmus, the capacity will form the international connectivity backbone for its planned network of AI Factories across Australia, enabling data movement between its domestic facilities and customers in the US and other global markets. While the deal represents one of the more substantial international connectivity commitments made by an Australian data centre or AI infrastructure company to date, the USD 300 million investment and 150Tbps capacity are contractual commitments under the agreement rather than capacity currently in active service.

Firmus co-CEO and co-founder Tim Rosenfield said the company recognised that connectivity had to be developed in parallel with its AI infrastructure buildout. "Building the compute is only part of the challenge. We also need to reliably connect that infrastructure to the world," Rosenfield said. "Securing up to 150 terabits per second of dedicated capacity gives us the scale and performance to connect Australian AI infrastructure directly with the United States."

APX East is being engineered as an independent, direct trans-Pacific route between Australia and the US, designed to bypass traditional chokepoints. SUBCO founder and co-CEO Bevan Slattery said the system was initially motivated in part by concerns about the resilience and capacity of existing international routes. In a discussion released alongside the announcement, Slattery described existing routes as increasingly "tired and overbuilt" and argued that new infrastructure was needed to strengthen the resilience of Australia's international connectivity.

A defining feature of APX East is its planned express route. Slattery noted that improvements in subsea system efficiency have reduced power consumption per amplifier by approximately 20 percent, enabling the system to span roughly 13,000 kilometres without requiring additional power injection and avoiding a traditional landing in Hawaii. The resulting route is intended to deliver a lower-latency direct connection between Australia and the US, although the companies' announcement places greater emphasis on capacity and overall connectivity rather than positioning latency as the defining requirement for AI workloads.

Rosenfield framed the cable investment as a natural extension of Firmus's vertically integrated approach to AI infrastructure. "We're building a network of AI Factories across Australia. But building the compute is only part of the challenge. We also need to reliably connect that infrastructure to the world," he said. Slattery echoed that sentiment, observing that the connectivity demands of AI are fundamentally reshaping demand patterns on international subsea routes. "The connectivity requirements of AI are fundamentally reshaping demand patterns on international subsea routes," he said.

Firmus is currently developing AI Factory projects in several Australian states, including planned facilities in Tasmania and South Australia, alongside other projects nationwide. The company has increasingly positioned its model as vertically integrated, spanning energy generation, data centre infrastructure, compute and connectivity. Rosenfield said the APX East agreement was intended to provide a long-term international route for the output of those facilities. "This is a 25-year investment in Australia's future," he said. "AI is fast becoming one of Australia's next major export industries, but that opportunity will only be realised if we invest in the infrastructure that underpins it."

APX East remains in the development phase, with SUBCO targeting commercial service in Q4 2028. The system joins SUBCO's existing portfolio of submarine cable projects, including INDIGO West, INDIGO Central and the Oman Australia Cable. For Firmus, the agreement secures a long-term international connectivity position several years before its planned AI Factory network is expected to reach full scale, effectively linking its Australian infrastructure strategy to the development timetable of a new trans-Pacific cable system.