European Club Association (ECA) chairman Andrea Agnelli, who is also on Uefa’s executive committee, said the “the green light has been given”.
He did not give any more details on how the tournament would be organised. “The current model needs modernising,” said Agnelli, 42.
Agnelli, who is also chairman of Italian champions Juventus, said: “A detailed assessment of the existing international match calendar is required prior to presenting a new model post-2024.”
Speaking at the annual general assembly of the ECA in Croatia, he said the third competition would increase the number of clubs involved in European football from 80 to 96.
The Champions League features 32 teams in the group stage and the second-tier Europa League has 48.
The Cup Winners’ Cup – for domestic cup champions – was scrapped in 1999.
In a statement, Uefa said it is “constantly reviewing the format of its competitions and is looking at a variety of options”.