Brian Gush is stepping down from the position of director of motorsport he has held since the beginning of the programme that climaxed with Le Mans victory for with the Speed 8 LM-GTP car.
The South African will be replaced on August 1, after the Spa 24 Hours on July 27/28, by current director of powertrain at Bentley, Paul Williams.
Gush joined Bentley in 1999 as director of chassis and powertrain, and masterminded the marque's factory return to international motorsport for the first time since 1930.
He was instrumental in getting the British manufacturer to take over a project that had originally been conceived to take parent company Volkswagen to Le Mans.
The programme to put VW's W12 engine in a new LM-GTP coupe designed and built by Racing Technology Norfolk in the UK was abandoned, but Gush identified it as the perfect tool to promote Bentley after its takeover by VW.
The project was given the go-ahead for Le Mans 2001 when Gush secured a supply of the twin-turbo V8 engines that powered sister marque's successful LMP900 cars.
Team Bentley finished third with the EXP Speed 8 at Le Mans in 2001 and fourth with an updated car the following year, before RTN built the all-new Speed 8 with a revised version of the Audi V8 developed specially for the car.
The two Speed 8s finished one-two at Le Mans in 2003.
#110 Bentley Team M-Sport Bentley Continental GT3: Jordan Pepper, Jules Gounon, Steven Kane, Rodrigo Baptista, Seb Morris, Callum MacLeod