Formula 1's managing director of motorsport, Ross Brawn has declared the arrival of new teams competing at a high level as the benchmark of Liberty Media's success in Formula 1 after 2021.

Negotiations are believed to be entering their final stages to determine what the regulations will be in three years time with an overhaul of car design and the revamp of the sport's financial structure, including a cost cap set to be included.

Changes to the current power unit were also expected, but with an apparent lack of interest from new manufacturers, it is now anticipated the engines will remain more or less the same but with a few tweaks.

With the possibility of adding three more teams to the F1 grid though, it is how well the current owners can attract interest that Brawn sees as a stronger barometer of Liberty's impact on the sport.

"Quite frankly, I can't see a new team coming in today because the revenue distribution and commercial distribution of funds and the technical regulations are too daunting," the Briton was quoted by F1i.com.

"We want to create an environment where there is a queue of professional organisations wanting to own and be a Formula 1 team."

In recent years only Haas has joined as a completely new outfit but their approach of buying as many parts in from Ferrari as permitted and have Dallara design their chassis has been quite controversial.

Even so, many see their model as perhaps the most viable way to be competitive in the sport, particularly after the failures of Manor, Caterham and HRT.

Regardless, Brawn simply hopes the regulations that are agreed on can create more Haas-type scenarios than those who joined the grid in 2010.

"We have always had this margin of teams at the bottom of F1 that are hanging on with their fingernails, and often falling, and we want quality competitors, not just people making up the numbers and saying they are in F1 if they can't step up," he explained.

"So we want the professional, well-financed, well-structured teams to be entering F1 in the future and that will be a measure of our success. But they won't come in today. I hope we can create the environment by then that makes it more appealing."