The legal dispute is over alleged misrepresentation

Yellowikis was set up in 2004 by Paul Youlten and 14-year-old Rosa Blaus, from Sussex, to let anyone create or amend a listings page.

The website has almost 5,000 listings for firms around the world.

Yell, which operates Yell.com, has said that users could confuse the website with its own services.

In a letter to Mr Youlten, solicitors acting for Yell said that Yellowikis was "plainly purporting to be associated with our client" and that the firm's intellectual property was under threat.

Website addresses

Yell wants Mr Youlten to shut down his site and hand over the four different website addresses for the service.

Solicitors have said they will seek damages and an injunction if he fails to respond to their requests.

A spokesman for Yell told BBC News: "Yell takes its brand and intellectual property seriously.

"Like any prudent brand owner it seeks to protect it."

Mr Youlten has contacted a solicitor, who is examining their request. He told BBC News: "We have not deliberately gone out to pretend to be Yell.

"It's one of those unfortunate things. We have a different sort of perspective than Yell.

"We consider ourselves to be a global business listing."

Business information

Yellowikis allows users to post Skype internet telephone numbers and video clips to listings, as well as traditional business information.

A wiki is a type of website that allows users to add, remove and edit most content.

The site is run as a hobby and not for profit, said Mr Youlten. "We have 400 to 500 register editors who update the pages as a hobby."

Users of the service are being asked to help choose a new name for the website and to make a donation to the legal defence fund.

"We hope they (Yell) understand that we did not mean to do it and that they will let us operate under a different name," he added.

Yell is arguing that the use of the name Yellowikis, the yellow logo used by the service and its positioning at the top left of the website "amounts to a misrepresentation which may result in third parties associating the website registered in your name with out client".