Three companies involved in Internet searches have complained that Google's search algorithms deliberately demote their sites because they are direct competitors.
The complaints have sparked a preliminary antitrust inquiry into Google's activities by the European Commission.
The search giant has carried out a pre-emptive strike in an official blog, suggesting that the whole thing is just a Microsoft plot.
"The European Commission has notified us," says the posting, "that it has received complaints from three companies: a UK price comparison site, Foundem, a French legal search engine called ejustice.fr, and Microsoft's Ciao! from Bing in Germany. While we will be providing feedback and additional information on these complaints, we are confident that our business operates in the interests of users and partners, as well as in line with European competition law."
Google points out that Foundem is a member of an organisation called ICOMP which is funded by Microsoft, and that Ciao! had been a long-time AdSense partner of Google's, with whom the company had always had a good relationship, until Microsoft acquired it and renamed it Ciao! from Bing in 2008, which is when the complaints started.
Google says it has a clear conscience, saying: "The question they ultimately pose is whether Google is doing anything to choke off competition or hurt our users and partners. This is not the case. We always try to listen carefully if someone has a real concern and we work hard to put our users' interests first and to compete fair and square in the market. We believe our business practices reflect those commitments."