Williams has agreed to sell a majority equity stake into sister company Williams Advanced Engineering.
Founded in 2011, WAE is the engineering services business of the Williams Group that owns the Formula 1 team. It employs over 300 people working in 40 different technology projects.
The stake will be sold to an independent private equity firm controlled by EMK Capital.
Williams said it will retain a minority interest in the WAE business.
WAE was the sole battery supplier for Formula E from its first season in 2014 until season four in 2018.
"We have rapidly grown WAE from an embryonic one client start-up, to a business with many clients in multiple sectors," said Williams CEO Mike O'Driscoll.
"The time is now right to sell a majority stake to enable WAE to further scale and develop its technologies. EMK Capital have a proven track record of success which will enable WAE to take advantage of these emerging opportunities and realise its full potential."
Craig Wilson, WAE's managing director added: "Williams Advanced Engineering has developed a strong reputation for providing energy-efficient advanced performance solutions to a diverse range of sectors and blue-chip clients.
"This expertise and our technologies in areas such as electrification, lightweight structures, aerodynamics and precision manufacture will become even more relevant and in-demand globally going forward.
"This new ownership structure will enable WAE to take advantage of these emerging opportunities and comes at a pivotal moment allowing us to further invest in new areas of capability and technologies in order to realise the full potential of the business."