In a somewhat ironic twist, Microsoft said this evening that it will file a formal complaint against Google tomorrow with European antitrust regulators.
Microsoft, which itself has been the subject of several antitrust probes in the United States and abroad, argues that Google is engaging in anticompetitive behavior in search, online advertising, and smartphone software, Microsoft general counsel Brad Smith wrote in a blog explaining the action.
"Google has done much to advance its laudable mission to 'organize the world's information,' but we're concerned by their broadening pattern of conduct--including walling off access to content and data--that is aimed at stopping anyone else from creating a competitive alternative," Smith said in a statement to CNET.
Google said Microsoft's announcement was no shocker.
"We're not surprised that Microsoft has done this, since one of their subsidiaries was one of the original complainants," a Google spokesperson said in a statement. "For our part, we continue to discuss the case with the European Commission and we're happy to explain to anyone how our business works."
Microsoft's Smith pointed out that Google's share of the search and search advertising markets in Europe is even higher than in the United States--around 95 percent. In contrast, Microsoft serves up about a quarter of search results in the U.S. through its Bing search engine and partnership with Yahoo, Smith said.
"Unfortunately, Google has engaged in a broadening pattern of walling off access to content and data that competitors need to provide search results to consumers and to attract advertisers," Smith said in his blog.
In his blog, Smith lists a half dozen instances in which he says Google is impeding competition, including limiting search results and Windows Phone access to YouTube, blocking access to content owned by book publishers, and restricting advertisers' access to their own data.
The complaint comes as the Justice Department reviews Google's $700 million bid to acquire airline flight and ticket information provider ITA Software. The deal has raised concerns among rival search engine companies such asand , including Expedia and Travelocity. They have all argued against the deal, saying that it would give the search giant a monopoly over online travel searches.
Google has come under increased scrutiny over the past several years as it has come to dominate the Internet. (CNET's Jay Greeneand what lessons it could learn from Microsoft's own antitrust woes.)
In February 2010, European regulatorsasking the company to explain how it ranks search results and advertising after complaints from European businesses such as Foundem, a price comparison site, and Ciao, another price comparison site owned by Microsoft. Those companies--Foundem in particular--have long complained that Google penalized their Web sites in search results under competitive pressure.
The Texas attorney general's office followed suit with its own antitrust review in September 2010,, including its formula for determining advertising rates and information on the company's closely guarded algorithms that run its search engine and AdWords, Google's system for displaying ads with keyword search results. are also said to be considering antitrust probes.
Microsoft, of course, is no stranger to accusations of predatory behavior. In 1998, for instance, the Justice Department accused Microsoft of illegally leveraging its Windows monopoly to give its Internet Explorer browser an unfair advantage. Because Internet Explorer was included as part of the operating system, it was the default browser for the majority of PC users. A federal judge ruled against Microsoft, leading the company to ultimately settle with antitrust regulators in 2002.
Updated March 31 at 12:45 a.m. with Google comment.