"Under certain conditions, mainly for reasons of geography and sustainable development, it might be possible to organize some events in other cities other than the host city, or even in other countries," Bach told the press.
"If a city says 'we don't have enough facilities for this sport, in this place, but there are some in a close city' why not?" he said.
In the Winter Games it already exists," Bach said.
"If two countries share a mountain, then why not share a bid?
"In the Summer Games, it is more about small neighbouring countries where distances are close.
"It is about giving smaller countries the opportunity to organize Games."
The plan which it is also hoped will help reduce bidding costs are among 40 recommendations which will be voted on at a meeting of IOC members in Monaco on December 8 and 9.
Another recommendation revealed at The Olympic Museum in Lausanne on Tuesday was to cap the number of sports and athletes, while giving a new sport or discipline an invitation to participate in the Games every four years.
"These 40 recommendations are like pieces of a jigsaw puzzle," explained Bach, a former Olympic gold medallist in fencing from Germany.
"When you put them together, a picture emerges that shows the IOC safeguarding the uniqueness of the Olympic Games and strengthening sport in society.
"We still want to limit the number of Olympic events but within this framework, we want to give more flexibility to sports which want to become Olympic," Bach continued.
"The Olympic Games mustn't become bigger, but more diverse."
The recommendation on reducing costs for bidding also includes cutting the number of presentations that are allowed by bidding cities and "providing a significant financial contribution from the IOC".
The IOC also want to have an "invitation phase" for bidding during which cities will be "advised about the opportunities this new procedure offers".
The recommendations were announced to a round table of athletes, many of whom contributed to the 'Olympic Agenda 2020' process.
"In the case of the Summer Olympics, it could be small countries with short distances," said Bach.
"Sometimes the distances within a country are less important than in a metropolis of 15 million people," he said.
"The host contract is always signed with a city but in reality it would be the whole country that would be the partner."
Occasionally, the IOC has allowed co-organization, particularly in the case of the Winter Games, among a host city and ski resorts, or for sailing events, often relocated during the Summer Olympics.