In a battle that could establish an important legal precedent on the Internet, the owners of (http://www.toronto.com) have filed a lawsuit against a small company using (http://www.toronto2.com).

BellActiMedia, Torstar Corp. and Ticketmaster Online-CitySearch Inc. claim that Toronto-based Friendship Enterprises is hurting toronto.com's business because the use of toronto2.com is confusing consumers and advertisers.

The three partners are seeking an injunction today from a Federal Court judge to prevent Friendship Enterprises from using toronto2.com, and seeking damages of $500,000.

The legal spat has the potential to set an important legal precedent if the three partners succeed in winning a court ruling that would allow them to stop another company from using a similar-sounding domain name.

George Jewell, general manager with toronto.com, said the three partners have made large investments to establish the Web site's brand. The two main issues, he said, are that the names are similar and both sites are involved in the same business of providing information about events and news in Toronto.

"We are not suggesting that every [domain] name with Toronto in it causes a problem," he said. "It really comes down to confusion it will cause consumers and advertisers."

Ritchie Sinclair, who started toronto2.com with Garth Cole earlier this year, said toronto.com's allegations are unjustified because there is a big question about who, if anyone, has the right to use Toronto in a domain name.

As much as toronto.com wants to believe that toronto2.com wants to piggyback on its success, Mr. Sinclair said the reality is that toronto.com is trying to capitalize on the good will and world-class status of the city of Toronto.

If anything, toronto.com's legal claims may raise questions about the similarity of domain names.