Adrian Sutil will not continue as the Williams Formula 1 team's reserve driver in 2016.
It is understood that the German is close to signing a deal outside of F1.
Sutil is known to be interested in the WEC and DTM, while Japanese Super GT may also appeal. He contested one GT race for TOM'S Toyota in 2006, during his F3 season in Japan.
Sutil was announced at Williams before last year's Malaysian Grand Prix.
However, he was in discussion with the team even before Valtteri Bottas's accident in Melbourne – which ultimately forced the Finn to miss the opening race of the season – put an extra focus on the need to have a reserve on hand.
Williams decided to sign a driver who had racing experience, and specifically with the hybrid V6, rather than promote tester Susie Wolff.
Sutil attended all the flyaway races with Williams in 2015, while waiting at home on standby for European events.
Although he sampled the car in the simulator, he never actually drove the FW37 on track.
He always regarded the Williams role as a temporary one as he looked for other opportunities.
It is not yet clear whether Williams will hire another experienced driver as reserve.
With Wolff now retired, Alex Lynn has been tipped to continue in a test role.