“This is a major breakthrough,” Dick Pound, a senior Canadian member, said. “We were at a dead-end situation with 28 sports. This provides the flexibility we need.”

Bach said host cities asking for certain sports must make a proposal to the committee and present an operational and financial model for their inclusion.

“This includes, in special cases, the number of athletes would go beyond the 10,500,” he said.

The new bidding process, meanwhile, is aimed at making the system cheaper and more flexible to attract future candidates — including the option of holding events outside the host city or country.

The votes came at a time when many countries have been scared off by the costs of hosting the Olympics, including the reported $51 billion associated with the 2014 Winter Games in Sochi. Several cities withdrew from the bidding for the 2022 Winter Olympics, leaving only Beijing and Almaty, Kazakhstan, in the running.

The new system makes the process more of an invitation and allows prospective candidates to discuss their plans in advance with the committee to tailor games to their own needs — and keep them affordable.

In the most radical change, cities will be allowed to hold events in both the Summer and Winter Games outside the host city or country, notably for reasons of geography and sustainability. This opens the door to joint bids by cities, neighboring countries or regions.

John Coates, the committee’s vice president, said holding events outside the host country would only be considered in exceptional circumstances. He said the idea would have to be raised in the early phase of bidding and would need approval from the committee’s executive board.