ZURICH — The World Cup will grow to 48 teams within a decade under a plan approved unanimously on Tuesday by FIFA’s governing council, an enormous expansion of soccer’s showpiece tournament that was hailed by supporters as a victory for inclusion but that was derided by critics as the latest money grab by an organization still emerging from a series of financial scandals.

The move, which will take effect in 2026, was the largest expansion, in percentage terms, for the World Cup since it went to 24 teams from 16 in 1982, and the first since it moved to the current 32-nation format in 1998.

The decision to expand was both political and financial. FIFA’s new president, Gianni Infantino, had pressed for the change when he ran for the presidency last year, as a way to invigorate the event and to include more countries. Expansion is sure to be popular in the vote-rich confederations of Africa and Asia that serve as any FIFA president’s power base. And few dispute that a 48-team World Cup would be a bigger, richer tournament, producing, by FIFA’s estimates, an additional $1 billion in television, sponsorship and ticketing revenue in the first cycle alone.

But critics of the plan argued that including less-pedigreed soccer nations would result in a diminished tournament, with nearly a quarter of FIFA’s 211 member associations earning a place every four years and more games jammed into a crowded international calendar. Infantino, well aware of both the electoral and the financial consequences of the change, pushed back.

“We are in the 21st century, and we have to shape the football World Cup of the 21st century,” Infantino said after the council’s meeting. “Football is more than just Europe and South America. Football is global.”

Anticipating questions about players’ workloads, Infantino repeatedly emphasized that, despite an increase in total games to 80 from 64, the tournament’s total length (32 days), the number of games played by the eventual winner (seven) and the number of stadiums (12) were the same for both the current and the expanded formats.

The World Cup has used a 32-team format since the 1998 tournament in France, and it will retain that structure for the coming competitions in Russia in 2018 and in Qatar in 2022. But beginning in 2026 — in a tournament for which the bidding to host has not begun — 48 teams will be placed into 16 three-team groups for the first stage, with the top two teams from each group advancing to a 32-team knockout round.

The charged question of how to allocate the 48 slots among the sport’s six continental confederations has yet to be determined, but it is certain to be the subject of fraught discussion, intense negotiation and high-stakes political calculus.

And Infantino said specific competition rules — such as a potential introduction of penalty shootouts to break ties in the group stage — would be determined in the years before the tournament.

Any plan to increase the size of the tournament field — at least four options for expansion were said to have been discussed on Tuesday, including variants for 48 teams and 40 teams — seemed specifically tailored to appeal to smaller soccer nations, particularly those in Africa, Asia and the Caribbean that often feel underrepresented at the World Cup. An expanded field of 48 teams in 2014, for example, might have included Egypt, Jamaica, Jordan, New Zealand and Tunisia.

The issue of expansion had divided the global soccer community since Infantino proposed it as part of his campaign to replace Sepp Blatter, who stepped down in 2015 amid a corruption scandal that led to the arrests of several members of FIFA’s leadership. The concept faced particular resistance in Europe, which has always had a disproportionate share of the automatic places in the tournament.

The European Club Association, which represents 220 clubs on the Continent, said in a statement that the current 32-team format was “the perfect formula from all perspectives.” It added, “We understand that this decision has been taken based on political reasons rather than sporting ones and under considerable political pressure, something E.C.A. believes is regrettable.”

Reinhard Grindel, the president of the soccer federation of Germany, the reigning World Cup champion, encapsulated other arguments against the plan last week when he publicly warned that the overall quality of play would be diluted and that the increased burdens on players could cause rifts between clubs and national teams.

“I think that even if you organized a World Cup with two teams, one of the two teams would be Germany,” Infantino said. “I hope that with time we can discuss it, and they can see the benefit for the world.”

Besides the current 32-team format and the new format approved on Tuesday, there were three other options on the table for the council to ponder: 40 teams with eight groups of five (88 games); 40 teams with 10 groups of four (76 games); and 48 teams, but with 16 seeds and a 32-team, single-elimination round before a 32-team group stage (80 games).

The World Cup tournament began in 1930, in Uruguay, with 13 teams, but as recently as 1978, it was still capped at 16, with only one entrant each from Asia and Africa.

Infantino, like his predecessors Blatter and João Havelange, had campaigned on the benefits of expanding the World Cup: more places for teams, more games to sell, more fans to engage in more markets and more money to make.

According to The Associated Press, FIFA’s internal calculations predicted that a 48-team tournament in 2026 would bring in $6.5 billion in revenue, an increase of $1 billion from the total it has projected for next summer’s tournament in Russia. Potential profit, FIFA said, could increase by around $640 million.

“It was done in a very good way, and the decision was made on the facts and figures, not on a wink and a nod,” said Victor Montagliani, the president of the Canadian Soccer Association and of Concacaf, the regional confederation of which the United States is a member. “Maybe the time has come that we don’t do things on a wink and a nod anymore.”

The bigger tournament will presumably present new logistical challenges for potential host nations, which will have to accommodate training sites and housing for 16 additional squads and their fans, but also at least a dozen stadiums capable of hosting games.

This would in theory be beneficial to the United States, which is viewed as a front-runner to host the 2026 World Cup, but also for China, which has expressed an eagerness to host as soon as possible.

Source: NYTimes