Microsoft Corp. said it was filing a formal antitrust complaint in Europe against Google Inc., alleging the Internet giant is squelching competition by limiting access to some of its data from YouTube and other services.
The complaint will be filed as part of the European Commission's ongoing antitrust investigation, launched in November, into whether Google has abused its dominance over Internet search in Europe at the expense of rivals.
Microsoft said it was the first time it had ever filed an antitrust complaint against a rival, and the move was another salvo in a bitter, long-running battle between the technology titans.
"Google has done much to advance its laudable mission to 'organize the world's information,' but we're concerned by a broadening pattern of conduct aimed at stopping anyone else from creating a competitive alternative," Microsoft General Counsel Brad Smith wrote in a blog post.
"We've therefore decided to join a large and growing number of companies registering their concerns about the European search market," Smith said.
Google said Thursday that it was not surprised by Microsoft's action because one of its subsidiaries, Ciao! from Bing, a product rating site that operates in several European countries, had filed the original complaint.
"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," Google said.
Smith said European regulators have found that Google has about 95% of the search market there and has taken advantage of that dominance "to the detriment of European consumers."
Google has restricted the ability of Microsoft's Bing and other rival search engines to gather data from YouTube needed to properly display search results, Smith said. Google also has blocked smartphones running Microsoft's Windows software from operating properly with YouTube — problems that iPhones and phones with Google's Android software do not have, he said.
"Microsoft is ready to release a high-quality YouTube app for Windows Phone," Smith said. "We just need permission to access YouTube in the way that other phones already do, permission Google has refused to provide."
Smith cited four other examples of what he said was Google's abusing its European search dominance, including limiting the ability of advertisers to access the data they give to Google so that they can also serve ads through competitors.
Sen. Herb Kohl (D-Wis.), chairman of the Senate's antitrust subcommittee, said the panel had been investigating "the fairness of Google search results" and complaints from rivals such as Microsoft that they were at a competitive disadvantage.
"These allegations raise important competition concerns, especially in light of Google's market share," Kohl said, "and we'll examine them more closely as we prepare for our antitrust hearing."