Williams are to provide the hybrid power technology developed for F1 last year for a new Porsche road car.
The Porsche 911 GT3 R Hybrid will use technology supply by Williams Hybrid Power.
Unlike their rivals, Williams developed a mechanical rather than electrical KERS, but did not run it during a race weekend in 2009.
The Porsche 911 GT3 R Hybrid will be revealed at the Geneva Motor Show.
Williams’ chief operating officer Alex Burns said: “Together we have worked to bring this technology forward to the point where it can be tested in a racing car and deployed in a road car. We hope that this will be just the start of the evolution of hybrid systems developed for Formula One moving across to applications where they can contribute to cleaner and more powerful vehicles.”
KERS is not being used by any teams in F1 this year but there are rumours a cheaper, standardised version of the technology may return in the near future.