Two teams have reportedly had applications to race in Formula 1 in 2016 turned down by the FIA.
Currently, 10 constructors compete in the world championship, with Gene Haas's North American outfit preparing to race next year.
However, the FIA told Autosport that two more would-be competitors registered their interest to join the grid in 2016, or 2017.
Motorsport's governing body has revealed that the two candidate teams were put through a "comprehensive diligence processes", but were not deemed to fulfil the criteria.
Renault have also been linked with a full return to F1, as they reportedly consider a buyout of Lotus.
