F1 has taken a step towards mandating standard gearboxes from 2021.

Planned to be part of Liberty Media's vision for the sport beyond the current Concorde Agreement, the standard gearbox idea has been put to tender by the governing FIA.

The FIA invited interested gearbox manufacturers to submit their proposals before March 15.

"The aim of single source supply is to retain current levels of gear change performance for all cars at a much reduced cost to the competitors while also removing the requirement for teams to design or source their own gearboxes," the tender said.

The document added that the "outer housing" of the gearbox will continue to be designed and produced by the teams, because that is important for design "freedoms for suspension and for the gearbox aero surfaces".