People with African-American sounding names are discriminated against when trying to get a room on Airbnb, a Harvard study says, suggesting many who use the website fail to share its vision of a "trusted community."

The San Francisco home-sharing startup, whose popularity has soared since it was founded in 2008, admitted in a statement that "bias and discrimination are significant challenges."

Researchers at Harvard Business School sent out 6,400 messages in July this year to hosts in five US cities -- Washington, Baltimore, St Louis, Los Angeles and Dallas -- from invented accounts looking to rent on Airbnb under distinctly black and white names.

"We find that requests from guests with distinctively African-American names are roughly 16 percent less likely to be accepted than identical guests with distinctively white names," the authors said.

"The difference persists whether the host is African-American or white, male or female."

The study concluded: "While information can facilitate transactions, it also facilitates discrimination."

It also noted: "Clearly, the manager of a Holiday Inn cannot examine names of potential guests and reject them based on race. Yet, this is commonplace on Airbnb."

One way around the problem would be to hide guest names, the study said.

Airbnb is among the most prominent of "sharing economy" startups, helping property dwellers rent out a room or their entire residence, while stirring concerns in the hotel industry about unfair competition.

In its statement to AFP Saturday, it said: "We are committed to making Airbnb one of the most open, trusted, diverse, transparent communities in the world.

"We welcome the opportunity to work with anyone that can help us reduce potential discrimination in the Airbnb community. We are in touch with the authors of this study and we look forward to a continuing dialogue with them."