(Reuters) – Online home-rental marketplace Airbnb Inc is one of three firms being considered to provide additional rooms for the 2016 Summer Olympic Games in Rio de Janeiro, as the city scrambles to accommodate visiting fans and athletes, three sources with direct knowledge of the situation told Reuters.

An Olympics contract would be a significant step into the mainstream for Airbnb, which allows home owners to rent their properties on a temporary basis. The company has become one of Silicon Valley’s most successful start-ups in the five years since it was founded by a trio of graduates from the Rhode Island School of Design and Harvard.

It would also potentially be the first time a major sporting event turned to the general public, and their extra rooms, to solve a short-term spike in demand for accommodation. By contrast, in London for the 2012 Olympics some home owners faced potential fines for renting their properties during the Games.

Airbnb declined to comment.

The two other short-listed firms are AlugueTemporada and Hotel Urbano.

Accommodation in Rio has long been a concern for the International Olympic Committee and it was singled out again as an area where progress needed to be made by Nawal El Moutawakel, IOC Coordination Commission Chairperson, at a news conference in Rio on Wednesday.

Speaking at the same conference, Carlos Nuzman, president of the Local Organizing Committee, said Rio already had 36,000 of the 40,000 or so rooms it needs for the Olympics. But he added that the committee was working to secure more accommodation.

“We might be in a position in which we can offer much more than forecast and the additional supply could reach 18,000, half of the total amount we have at the moment,” Nuzman said.

Partnering with a company such as Airbnb could also help to provide more economic options for visiting fans. The soccer World Cup, held in Brazil in 2014, was criticized for the cost of accommodation, particularly in Rio where the final was played.