Providing Web links to copyright-protected music is enough to make a site legally liable, an Australian court ruled in a case that created legal uncertainty for search engines around the world.

The full bench of the Federal Court, the country’s second-highest court, has upheld a lower court ruling that Stephen Cooper, the operator of the Web site in question, as well as Comcen, the Internet service provider that hosted it, were guilty under Australian copyright law.

They were accused of authorizing copyright infringement because they provided a search engine whose results linked to songs available for illegal download, even though the Web site did not store the music files directly.

Cooper had argued that his Web site performed a function comparable to search engines such as Google Inc., which is based in Mountain View, Calif.

But Judge Catherine Branson wrote in Monday’s ruling that “Cooper’s assumption that Google’s activities in Australia do not result in infringements … is untested.”