The European Commission (EC) has notified Google (GOOG) that it will begin an informal investigation into complaints from three European companies regarding Google’s page ranking on search results. The three companies making the complaints are Foundem, a UK price comparison site; ejustice.fr, a French legal search engine; and Microsoft’s (MSFT) Ciao! from Bing, a Germany-based price comparison and shopping site.

Google’s page ranking is what made the search engine so popular to begin with, and the techniques that other web sites can use to optimize their position in Google’s search results are well-established and well-known. Now that Google owns 70% of the U.S. search market and perhaps as much or more elsewhere around the globe, competitors can yell about anti-trust and anti-competitive behavior at every possible instance.

But is the yelling justified? In a New York Times article, Foundem co-founder Adam Raff argues that search engines such as Google, Yahoo! (YHOO) and Microsoft’s Bing “have become the Internet’s gatekeepers” and that “they are now as essential a component of its infrastructure as the physical network itself.” He goes on to say that not only should regulators support net neutrality but that policy makers should also enforce “search neutrality: the principle that search engines should have no editorial policies other than that their results be comprehensive, impartial and based solely on relevance.”

When Google introduced what it called “universal search” in 2007, the company started fiddling with the way it returned its search results. Google-branded results began showing up at the top of the results page, pushing other returned pages further down, reducing the likelihood that users would click through to those pages.

Google doesn’t deny that is how its engine works, and the company has published guidelines for advertisers and webmasters detailing universal search. But that is not likely to stop the complaining from competitors.

The important issue for Google to defend is that its page ranking does not violate anti-trust rules in every country where its search engine is available. Which is every country, and which puts Google in a position not unlike Microsoft, who owns some 70% of the global operating systems business.

The U.S. spent a year reviewing Google’s purchase of online ad serving firm DoubleClick, and the Department of Justice blocked an attempt by Google to team up with Yahoo! on a search advertising deal. The Google Books project is also getting a lot of scrutiny and some heat from some authors, publishers and competitors.

How easy or difficult it becomes for Google to defend itself against these claims is not as important as the fact that all these claims will be made. The time, effort and money that Google must spend to fight off the claims are time, effort and money that the company can’t spend more productively.

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