The European Clubs Association claim changes must be made to top continental competitions in order to "help the growth" of minor leagues.
UEFA's strongest sides must consider reforms to the Champions League to help address the imbalances with the current system, according to the European Clubs Association (ECA).
The ECA, spearheaded by Juventus president Andrea Agnelli, is pushing to revamp the structure of continental club competitions, with proposed changes reportedly including promotion and relegation.
Preliminary discussions with UEFA have taken place but the ECA's attempted overhaul has been met with considerable opposition.
LaLiga and the Premier League have made clear their disapproval at the plan, while the European Leagues - a representative body - claim only a "few rich and dominant clubs" would see the benefits.
However, ECA vice-chairman Aki Riihilahti disputed that view.
"The current system doesn't work for most sides, and if we want to keep professional and grassroots football alive, we have to take into consideration the different local situations, whilst at the same time developing it at higher levels," said Riihilahti.
"Playing in more relevant competitions would help the growth of minor leagues."
Concerns "swept away", claims Agnelli
Chairman Agnelli insisted that changes are a long way from coming to fruition, yet he claimed to have "swept away the concerns" of some clubs who attended a two-day summit in Malta.
"There are several problems for which we must find a solution and to do so we must put ourselves in the shoes of others and have an overall vision of European football," Agnelli said.
"We are at the beginning of a long process, but what matters is that the clubs have shown a willingness to engage positively and with intellectual honesty, in order to address the reform of European football in the best way.
"In September, in Nyon, we will share our points of view and many things will still need to be discussed, but we are open to a transparent conversation and we want the satisfaction of all European football, not just some clubs."
Former Manchester United goalkeeper and Ajax CEO Edwin van der Sar added: "Not everyone was born in Manchester or London.
"We must also find a way for those who come from leagues, such as Poland, Portugal, Greece, Turkey and Holland to grow at a European level."