The highly respected Nielsen was originally appointed at the start of this year, having had a lengthy career in grand prix racing at a number of teams including Lotus, Tyrrell, Benetton, Williams and AlphaTauri prior to working at Formula 1 management.
He worked closely with F1 race director Niels Wittich and took responsibility at the FIA for all sporting matters in F1, including the development of race control and the remote operations centre, as well as future updates to the sporting regulations.
However, off the back of a challenging year for the FIA which has faced scrutiny over a number of issues, including track limits and president Mohammed Ben Sulayem’s style of leadership, high level sources have indicated that Nielsen has decided against continuing.
There are suggestions that he had grown frustrated with the way the F1 operations were being run and the direction things were heading.
Source: Autosport