The European Champions League will see an increase of four teams to 36 and the present group stage replaced by one single league from the 2024/25 season, UEFA said on Tuesday.
The revamp of European football's premier club competition will see each team play eight league games -- four home and four away -- as opposed to six in the group stage.
The top eight sides in the league will qualify automatically for the knockout stage, while the teams finishing in ninth to 24th place will compete in a two-legged play-off to secure their path to the last 16 of the competition.
"We are convinced that the format chosen strikes the right balance and that it will improve the competitive balance and generate solid revenues that can be distributed to clubs, leagues and into grassroots football across our continent," said UEFA president Aleksander Ceferin.
Ceferin and UEFA will be hoping the reforms -- passed unanimously by their executive board -- will kill off once and for all any thought of the rebel Super League making a reappearance.
Twelve of Europe's biggest clubs signed up to the proposed new competition last April but it collapsed within days following a fierce backlash from their own players and fans, as well as governments and football's governing bodies.
Nine clubs distanced themselves from the project but Real Madrid, Barcelona and Juventus remain on board with the concept.
UEFA had stepped back after consulting with various parties -- including supporters -- from having 10 league matches and allocating two of the four new places to teams based on club coefficient.
The four places will go to the club ranked third in the championship of the association in fifth position in the UEFA national association ranking.
Another will be awarded to a domestic champion by extending from four to five the number of clubs qualifying via the so-called 'Champions Path'.
The final two places will go to the associations with the best collective performance by their clubs in the previous season (total number of points obtained divided by the number of participating clubs).
Those two associations if it had been judged on this season based on the collective performance of their clubs would be England and the Netherlands.
Similar format changes will also be applied to the UEFA Europa League (8 matches in the league stage) and UEFA Europa Conference League (6 matches in the league stage) and both will also include 36 teams in the league phase.
Ceferin revelled in the moment of succeeding in pushing through the reforms.
"I am really pleased that it was a unanimous decision of the UEFA Executive Committee, with the European Club Association, European Leagues and National Associations all agreeing with the proposal made," said Ceferin.
"Another proof that European football is more united than ever.
"Qualification will thus remain purely based on sporting performance and the dream to participate will remain for all clubs."