Masi was given the race director job after Charlie Whiting passed away on the eve of the 2019 Australian GP, and he held it for three full seasons until last year’s Abu Dhabi GP controversy proved to be the trigger for his departure from the job in February.
He returned to Australia in April, but remained an employee of the FIA, while his future role remained under discussion.
The FIA confirmed on Tuesday that Masi has now formally parted company with the organisation.
“It has been a pleasure and honour representing the FIA as the single-seater sporting director and FIA Formula 1 race director and safety delegate since Charlie’s unexpected and tragic passing in Melbourne 2019,” Masi said in a statement provided to Autosport.
“Having worked on various projects around the world with the federation and its member clubs for over a decade prior to my appointment, I have now decided to leave the organisation and relocate back to Australia to be closer to my family and friends.
“I am proud to have worked in partnership for many years with the various FIA member clubs, Formula 1 Group, the competitors, promoters and circuit operators and my colleagues and team internally at the FIA.
“I will always treasure these lifelong relationships and friendships that I have developed throughout my journey to date.”
In thanking Whiting for giving him a chance to serve as deputy race director, Masi stressed that his promotion to the main job came much earlier than had been planned.
“In particular, I am eternally grateful to Herbie Blash and the late Charlie Whiting for identifying me as a future successor in 2018, a role that I was looking forward to shadowing and learning from Charlie for many years prior to his shock passing,” he said.
“I also pass on my sincere appreciation for the support and guidance during my tenure of the former FIA President Jean Todt, Stefano Domenicali, and my dedicated FIA single-seater team.
“I extend my appreciation to the tens of thousands of dedicated volunteers and officials that allow motorsport to happen each and every day around the world, as the safety of the competitors and officials has always remained my highest priority.”
He concluded: “Thank you to the FIA president, Mohammed Ben Sulayem and his presidential team for their personal support since their appointment and I wish them the best for the future.
“The personal support of my family, friends, and colleagues globally during this journey and particularly in the last few months can only be described as overwhelming and something that I will forever cherish.”
It’s understood that Masi has yet to decide what path his career now takes.