French company 1PlusV operates a number of subject-specific, or 'vertical', search engines including ejustice.fr, which was one of a number of companies whose complaints led to a European Commission competition investigation.
"1PlusV accuses Google of pursuing a strategy of foreclosure against vertical search engines," it said in a statement, according to news agency Bloomberg. It told the news wire that the way that Google operates its sites violates web guidelines and even its own rules in some cases.
1PlusV founder Bruno Guillard told Bloomberg that it had been forced to abandon its own search technology in order to have access to Google's advertising platform AdSense.
"They bundle their AdSense program with their search technology and we were obliged to move from our own technology for search to the Google technology to have access to AdSense," he said. "So the first problem we had was the bundle approach between AdSense for search and Google technology and we were obliged to move our own technology to the Google one."
The company told reporters in Brussels this week that it had filed an additional complaint with the Commission about Google's conduct to add to last year's ejustice.fr complaint. It said that restrictions on Google's AdSense platform prevented 'vertical' search engines from making money.
The original complaint was filed in conjunction with UK search engine Foundem and price-comparison site Ciao, which was bought by Microsoft in 2008. The companies claimed that Google manipulates search results to put competitor search companies at a disadvantage.
The Commission announced in December that it would investigate the claims, which Google denies.
"The opening of formal proceedings follows complaints by search service providers about unfavourable treatment of their services in Google's unpaid and sponsored search results coupled with an alleged preferential placement of Google's own services," said a Commission statement in December. "This initiation of proceedings does not imply that the Commission has proof of any infringements. It only signifies that the Commission will conduct an in-depth investigation of the case as a matter of priority."