A California judge has granted a motion by Google to dismiss a lawsuit by KinderStart.com over the site's page ranking.

The website alleges that Google is responsible for a 70 per cent drop in site traffic and 80 per cent drop in advertising revenue after the search firm dropped the site in its search rankings.

KinderStart.com had alleged that Google's decision to lower the site's ranking amounted to a violation of its free speech rights and attempted monopolisation.

The company also charged that the reduction in page ranking was retaliation by Google for decreased advertising spending.

The judge presiding over the case squashed the free speech claims, pointing out that Google does not have any legal obligation to ensure free speech rights in this case.

Although he dismissed KinderStart.com's monopolisation claims, the judge allowed the website to amend its case.

This allows the site to further clarify where and how Google coerced sites into purchasing advertising to guarantee a higher page ranking, and that the search engine consistently ranks websites lower than Yahoo and MSN.

The site got a chance to amend its case on several other points, including on a complaint that Google is a 'common carrier' and as such is banned from discriminating against the services that it transmits.

"There are very few novel or surprising aspects of this ruling," commented Eric Goldman, a law professor with the Santa Clara University School of Law.

"It's pretty clear that the judge thinks that some of KinderStart.com's claims have no chance even with re-pleading, but the judge apparently has decided to give KinderStart.com that chance rather than just shutting the door. "