(AP) -- A French creator of specialized search engines on Tuesday filed a new complaint with the European Union about alleged anticompetitive behavior by Google Inc., a reminder of the regulatory hurdles the online search giant faces in the region.
The latest claim comes from 1plusV, which runs so-called vertical search engines that specialize in subject areas like law, music and culture.
It said that between 2006 and 2010 Google prevented companies using vertical search technology from using its online advertising service AdSense. 1plusV says Adsense is "the only truly effective way of obtaining targeted advertising on a search engine."
The strategy keeps alternative search providers from growing and competing with Google, 1plusV company said in a statement.
1plusV is the parent company of legal search engine eJustice.fr, which already complained to the EU last February, claiming Google unfairly removed it from its search results.
That complaint, along with others, triggered the European Commission, the EU's antitrust regulator, to launch an in-depth probe of Google's business practices in November.
The new complaint "brings to the notice of the Commission a series of new abuses ... as well as additional proof of the abuses already complained of last year," 1plusV said in a statement.
It said that in the weeks following its original complaint, Google retaliated by delisting other sites published by 1plusV. For eJustice.fr, Google's decision to remove it from its search results was "catastrophic in terms of its traffic," 1plusV said.
Google has said that ranking on its search results depends on how valuable a given site is for its users. It has in the past advised companies to improve their websites to help them move up in the results list.
But 1plusV said Tuesday that Google doesn't stick to that policy, noting some of the previously removed sites were relisted in December, even though they hadn't been modified.
"The relisting is in complete contradiction with the Google argument that eJustice.fr was delisted because it provided no value to the Internet user," 1plusV said, adding that the sites were relisted shortly after the Commission launched its investigation.
Google said Tuesday that it has been working closely with the Commission to explain its business model. "While we have always tried to do the right thing for our users and advertisers, we recognize that there's always room for improvement," the company said in a statement.
The Commission said that once it receives the new complaint it "will give Google the opportunity to comment on the allegations raised before deciding on what, if any, further steps to take."
If Google is found guilty of abusing its dominant position in the search-engine or advertising markets the Commission can fine it up to 10 percent of annual revenues, which reached $29 billion in 2010.
Explore further: Online piracy thrives in Internet cloud: study (Update)