The proposals will be submitted to the FIFA Council at its next full meeting in Bahrain in May for a final decision, FIFA said.
Under the proposal, made by the FIFA Bureau, for the enlarged tournament beginning in 2026, Europe would get 16 direct places, Africa nine, Asia eight, South America six, CONCACAF six and Oceania one, totalling 46 teams.
The host nation would qualify automatically and its slot would be taken from the allocation of its confederation.
In the most innovative part of the proposal, the two remaining places would be decided by a six-team playoff tournament which would take place in the World Cup host nation, possibly in the November before the finals, FIFA said.
That tournament would include one team from each confederation, except UEFA, and an extra one from the continent of the host country.
FIFA decided in January to increase the tournament from 32 teams to 48.
The current allocation is 13 places to Europe, five to Africa, four to Asia and South America and three to CONCACAF.
Asia, South America, CONCACAF and Oceania also get a place in two inter-zonal playoffs.
The proposal shows how football has grown around the world over the last 40 years.
As recently as 1978, when the World Cup had only 16 teams, Africa and CONCACAF were given only one place each while Asia and Oceania had to share one place between them.
According to the FIFA world rankings, the top nine teams in Africa currently include Burkina Faso, who have never played at a World Cup, and Democratic Republic of Congo, who took part only once as Zaire in 1974.
CONCACAF'S top six include Panama and Haiti while St Kitts and Nevis are seventh.
Asia's top eight include Uzbekistan and Qatar while China are ninth and Syria 10th.
UEFA president Aleksander Ceferin said in a statement that he was "satisfied" with the proposal.
"We feel that UEFA will be fairly represented with a total of 16 national associations competing in the new format of the World Cup," he said.
(Writing by Brian Homewood in Berne, editing by Mitch Phillips and Clare Lovell)
