SAN FRANCISCO (Reuters) - Airbnb sued the city of San Francisco on Monday (June 27), arguing that a recent ordinance which requires hosts to register with the city violates the online home-sharing company's free speech rights.

A San Francisco law slated to take effect next month requires companies like Airbnb to verify that rentals have a valid registration number issued by the city. The ordinance would impose on the company fines of up to US$1,000 (S$1,362) per day for each offence.

Airbnb's lawsuit claims that the ordinance violates federal communications laws and asks a judge to block it. The law cannot fix San Francisco's housing crunch, the company said in a blog post.

"This legislation ignores the reality that the system is not working and this new approach will harm thousands of everyday San Francisco residents who depend on Airbnb," the company said.

Matt Dorsey, a spokesman for the San Francisco city attorney's office, said nothing in the ordinance punishes Airbnb for their hosts' content. Rather, the ordinance is intended to facilitate tax collection, he said.

"In fact, it's not regulating user content at all - it's regulating the business activity of the hosting platform itself," Dorsey said in an email.

The case in US District Court, Northern District of California is Airbnb Inc vs City and County of San Francisco, 16-03615.