According to Powerhouse, the potential buyer will now invest directly in Invert's current capital raise to ensure it achieves its required holding level of Invert shares.
Invert is undertaking an initial capital raise of A$4m which is proceeding "terribly well," said Powerhouse chief executive Paul Viney.
The book is expected to be closed in a week or two. He declined to name the potential buyer.
Invert will subsequently look to raise around a further A$6m to "enable M&A expansion throughout Europe," he said.
The second part will take place over the next 12 months, according to Viney.
Invert Robotics has developed a novel climbing robot system for remote inspection services in the dairy and food processing sectors as well as the aviation industry.
According to Powerhouse it has an enterprise value of $10.7m and seven employees.
Powerhouse shares recently traded at 35 Australian cents on the ASX and have more than halved this year.