The value of the deal was not disclosed.
The two already collaborated on Position Partners' automation solutions.
"Since 2019, we have launched initiatives that have been fostered through the Mitsui network, notably in our mining business," Position Partners CEO Martin Nix said.
"Mitsui has also enabled collaborations for two of our key services: Tokara, construction site remote access and data transmission solution; and AllDayRTK, our national GPS network.
"Supporting new growth opportunities and leveraging our capabilities will provide an even better experience for customers. Our Southeast Asia and mining systems businesses can expect to be significant beneficiaries of Mitsui's post investment strategic support.
"Mitsui recognises that our ability to deploy solutions to sites with various types of machinery, systems and software is critical to realising the full potential of digital innovation in the construction, mining and geospatial industries."
The existing Position Partners executive team will remain intact, with three Mitsui representatives to join the board.
"This announcement represents an exciting next step in our company's evolution and growth. More opportunities for customers, employees, suppliers and partners can be expected," Nix said.