The meeting, originally scheduled for September 11 at the Nyon headquarters of European football's governing body, was set to bring together the European Club Association (ECA) and European Leagues, which represents leagues from across the continent.
But in a letter seen by AFP and sent to ECA president Andrea Agnelli and head of European Leagues Lars-Christer Olsson, UEFA president Aleksander Ceferin said he had "decided to postpone the meeting of 11 September".
"We are currently in the process of gathering feedback from our national associations and I feel –- more generally –- that a new discussion now would be premature as we are analysing feedback and proposals coming from different parties," Ceferin wrote.
Ceferin added that he did not "expect to make a decision this year" on the changes to the format of European club competition from 2024, which were proposed by the ECA and have faced fierce opposition.
Asked by AFP, UEFA said no new date for the meeting had been set. The summit was originally scheduled for the day after the ECA's General Assembly in Geneva.
The postponement comes amid fears over the ECA's proposal, pushed by Agnelli, of a competition reportedly spread over three 'divisions' would threaten domestic competitions.
According to reports, the top division would be made up of four groups of eight teams, with the top six in each qualifying for the following edition regardless of where they finish in their domestic leagues.
Agnelli has defended the plans as an attempt to save smaller clubs from "the protectionism of the big five leagues".
However the Premier League, which had four teams in the finals of the Champions League and Europa League last season, has unanimously opposed the project.
In June 15 clubs in the Italy's Serie A, where Agnelli's Juventus have reigned supreme for almost a decade, reportedly opposed the reforms, with Juve the only side to openly support the changes.
The rebelling Serie A teams, which included Napoli and Lazio, believe the plans could lead to a decrease of as much as 35 percent in top-flight revenues.
Seven Spanish clubs, but not Real Madrid nor Barcelona, are also against the plans, along with the all the Bundesliga clubs, while 17 Ligue 1 sides came out against the project while Paris Saint-Germain, Lyon and Marseille abstained.
In May Bayern Munich CEO Karl-Heinz Rummenigge slammed the reforms, saying that "Champions League is already the best competition in the world".