Bertrand ends a decade-long spell with the FIA, where he most recently served as its director of Formula E and innovative sport projects, and oversaw the integration of the Gen3 era in the championship as one of the governing body's key figureheads.
The Frenchman was also involved with the start of the FIA Motorsport Games project, which has recently completed its second edition at Paul Ricard.
Bertrand will hence be in charge of overseeing Mahindra's fortunes over the Gen3 period, in which the team has opted for a revised driving line-up - adding 2016-17 Formula E champion Lucas di Grassi to the squad to partner Oliver Rowland.
“I am delighted and extremely excited to be joining Mahindra Group to lead its racing activities," said Bertrand.
“I have been privileged to witness the growth of the Mahindra Formula E team and feel proud to have now been entrusted with driving the team to even greater performance and results.
“The coming months will be tough and will require a lot of hard work, but the goal is clearly to be on the pace in what promises to be an ultra-competitive field of manufacturers and teams.
“It is a new chapter and major challenge in my career, and I cannot wait to get started!”
Bertrand's prior involvement in the development of the Gen3 car is likely to be a bone of contention between other teams and Mahindra, although the route from the governing body to join a competing team in a championship has been previously travelled in motorsport.
Within Formula 1, Marcin Budkowski was placed on a three-month gardening leave period by the FIA in 2017 before leaving to take up a role with Renault. Ex-deputy race director Laurent Mekies also left the FIA in 2018 after a year to take up the sporting director role at Ferrari.
"The FIA can confirm that Frederic Bertrand, formerly Formula E and Innovative Sport Activities Department Director, has resigned from his position to seek other opportunities," read a statement from the FIA provided to Autosport.
"The FIA thanks Frederic for his many contributions to the organisation over the past 10 years and wishes him well in his future endeavours."
Bertrand's predecessor Gill left Mahindra in September having served as team principal and CEO since Formula E's inception, and is currently on a period of gardening leave until next year.
