The International Olympic Committee (IOC) on Tuesday voted in favor of awarding hosting rights for the 2024 and 2028 summer Olympics at the same session in September, pending agreements with Paris and Los Angeles.
The two cities are the only ones left in the race to stage the 2024 Games and the IOC will next seek a "tri-partite" agreement with them.
That could mean either that one city will accept the 2028 Games before the session in September or that each would be willing to accept 2028 if it is not awarded the 2024 Olympics.
The IOC has been desperate to overhaul its bidding process after four cities - Hamburg, Rome, Budapest and Boston - pulled out of the 2024 race, scared off by the size, cost and complexity of hosting the Games.
Should there be no three-way agreement, the vote at the session in Lima, Peru, on Sept. 13 will be a straightforward selection of only the 2024 host city.
"This (double awarding) is a golden opportunity," said IOC President Thomas Bach. "It is hard to imagine something better. This is why the IOC asked its vice presidents to study how to make the most of this unique constellation."
IOC Vice President John Coates said there would not be a double awarding during the 2026 winter Games bid process.
"We are not contemplating that this will be the normal procedure," Coates told the IOC session.
Bach has said in the past he did not want any "losers" in the bid process, aware of the dip in popularity of the Olympics among the world's major cities.
Four more had pulled out of the 2022 race two years ago while two did not even bid after plans were killed off by local referendums.
Before the vote on Tuesday both Paris and Los Angeles presented their bids to the 83 IOC members present, with the French capital receiving a major boost from the presence of President Emmanuel Macron, who addressed the session.
(Editing by Ed Osmond)