Uefa also promises that annual prize money to the 32 group-stage teams – worth 1.32 billion euros (£1.13 billion) this season – will be “increased significantly” for the three seasons through 2021.
Uefa announced the deal on Friday after months of talks with the influential European Club Association, whose members raised an old threat of breaking away to form a closed Super League dominated by the rich and storied elite.
Still, the deal to give 16 guaranteed group-stage places instead of 11 currently to clubs from the Spanish, German, English, and Italian leagues will inevitable squeeze teams from lower-ranked leagues, including Scotland.
“Uefa, the clubs, the leagues and the national associations speak with one voice on these matters,” Uefa said in a statement.
Italy is the big winner in the new agreement, which had to be completed this year to let Uefa start selling broadcasting and sponsorship rights for the 2018-21 commercial cycle.
From 2018, the group stage will include the top four finishers in the previous season’s La Liga, Bundesliga, English Premier League, and Serie A who will have direct entry. They will avoid the risk of losing in the playoff qualifying round and miss tens of millions of euros (dollars) in Uefa prize money.
In recent seasons, Italy typically has had only two group-stage teams because Serie A’s third-place team often loses in the play-offs. Roma was eliminated this week by Porto, giving fifth-ranked Portugal three teams in the groups draw on Thursday.
Other changes announced on Friday are also likely to benefit the big four leagues.
From the 2018 season, a Champions League groups slot will be guaranteed to the previous season’s Europa League winner. Currently, the Europa winner can be made to qualify through the play-offs.
Sevilla has won the Europa League in both years since the incentive was offered, and Spain had five teams in the Champions League groups last season.
Uefa has helped storied clubs who have slumped in recent seasons and would slip in the rankings which determine draw seeding.
“Historical success in the competition will also be acknowledged in coefficient calculation (points for previous European titles),” Uefa said.
That is effectively a cushion to prop up former European champions who have failed to qualify for the Champions League in recent seasons.
Manchester United, Liverpool, Chelsea, AC Milan and Inter Milan – all Champions League winners in the past 12 seasons – were missing from Thursday’s draw.
Uefa has yet to resolve how the changes will have a knock-on effect on smaller clubs’ access to the Champions League groups.
Currently, 22 of the 32 slots are guaranteed to teams from 12 different leagues, including titleholders from Belgium, Switzerland, and Turkey. Those look to be at risk.
Details of how the deal will squeeze clubs such as Belgium’s Bruges and Switzerland’s Basel will be “finalised by the end of the year,” Uefa said.