London 2012 Olympics organisers have released more than 120,000 hotel room nights back onto the open market, they announced.
They confirmed that some 20 percent of the room nights they had reserved in London would be returned to hotels to offer up to other customers.
The spaces had been reserved to provide accommodation for media, global sport federations, the International Olympic Committee, Games workers and sponsors.
The rooms at more than 200 hotels, range from five-star to budget accommodation.
Hundreds of thousands of visitors are expected to flock to London for the July 27 to August 12 Games, whether ticket holders or not.
As part of the bid to stage the 2012 Olympics, agreements had been struck with hotels to provide more than 40,000 rooms, representing more than 600,000 room nights during the period.
But part of the deal was that the organisers promised to return any unwanted rooms to the hotels so they could sell them in time for the Games.
"The hotel industry in London got behind the bid to stage the Games in the most extraordinary way and that support helped us across the line," London Olympics chief executive Paul Deighton said.
"We always promised that we would not hold on to hotel rooms we didn't need but return them to the individual hotels at the beginning of 2012.
"We are now doing this and I hope that this enables the hotels to continue with their planning for this summer as we all work together to stage a spectacular Games."
Sandie Dawe, the chief executive of the VisitBritain national tourism agency, said: "The fact that such a wide spread of rooms in London will now be made available to the public is great news for overseas visitors wishing to come to the UK to experience the Olympics and all the other wonderful festivities that are taking place."
However, some in the tourism industry warned that prices had risen too fast before the new rooms were offered and many potential visitors have been put off staying in London.
Neil Wootton, managing director of sightseeing operator Premium Tours, told The Independent newspaper: "Prices have been so high that tourists are moving elsewhere."