FIFA have unanimously decided on a 48-team World Cup from 2026 onwards during their Council meeting here today, it has been announced.
The format will consist of 16 groups of three teams, replacing the current 32-team competition.
This means that either 79 or 80 matches will be played throughout the tournament, depending upon whether the third place play-off remains.
Two teams will progress from each group to a knock-out stage, meaning every participant is guaranteed at least two matches.
No decision, however, has yet been made on what weighting each continental confederation will be given for the extra places.
A proposal to consider penalty shoot-outs during the group phase to avoid draws and possible dead rubbers has also not yet been decided upon.
The FIFA Council unanimously decided on a 48-team #WorldCup as of 2026:— FIFA Media (@fifamedia) January 10, 2017
16 groups of 3 teams. Details to follow after the meeting.
"We were very pleased with the meeting, which took place in a very good atmosphere," said FIFA President Gianni Infantino.
"There is not a big change except for format and giving many opportunities for more teams.
"Tournaments will still last 32 days, the winner will still play seven times, and 12 stadiums will still be required.
"The upside is having 16 more countries, some of which would never have dreamed of participating before.
"We have to shape the football World Cup in the 21st century and we now think we have a format which brings benefits without negatives."
FIFA officials were keen to claim afterwards that the decision was a "football" one which would serve to enhance opportunities for "smaller" nations to participate and prosper in the way the likes of Wales and Iceland did at the 2016 European Championships.
A statement claimed the decision was taken "following a thorough analysis, based on a report that included four different format options".
It added: "The study took into account such factors as sporting balance, competition quality, impact on football development, infrastructure, projections on financial position and the consequences for event delivery."
The exposure in the period between qualifying for and participating in the quadrennial event would also play a pivotal role in developing the game in qualified nations, Infantino claimed.
Generating more finances and ensuring Infantino's power-base at the head of the organisation are thought to be other key objectives, though.
A report circulated among the FIFA Council members has predicted an increased total revenue of $6.5 billion (£5.3 billion/€6.2 billion).
This would mark a 25 per cent growth on the record figures recorded at the 2014 World Cup in Brazil.
The weighting of the additional teams could not be decided until a "couple of years" before the 2026 tournament, Infantino added.
Under the latest proposals, it is thought that Europe may get an additional three, from 13 to 16, while South America's share would rise from 4.5 to six.
Asia and Africa would each gain four additional places to respective totals of 8.5 and nine - with the half place the result of a play-off with a team from another continent - while Oceania would now be guaranteed one position.
If confirmed, the greater share for Asia and Africa would greatly boost Infantino's support in these areas.
He refused to give a specific view on the weighting today, but did speak about changing a current situation in which the Confederation of African Football have 54 members to UEFA's 55 - but have eight less places in the World Cup.
European representatives indicated that they would be "satisfied" with having 16 places.
This would presumably mean having one in each of the groups and the possibility of all 16 progressing.
"We would not be prepared to accept anything less than 16," said Italy's Council member Evelina Christillin afterwards.
FIFA's statement added that: "Over the course of its next meetings, the Council is set to discuss further details regarding the competition, including the slot allocation per Confederation."
The issue is due to be discussed again at the next meeting of the FIFA Council scheduled to be held in Manama in Bahrain on May 9 before the 67th FIFA Congress.