Microsoft has filed a formal complaint to the European Commission (EC) over Google's search practices as part of a wider anti-trust investigation already underway.
The firm's general counsel, Brad Smith, outlined numerous issues with Google's practices in a detailed blog post, claiming that the anti-competitive situation is even worse in Europe than in the US.
Among Smith's arguments is that Google is stopping Microsoft's Bing platform from indexing YouTube results, which he said means that internet users will naturally head to Google over rivals to receive video search result from the site.
"Since [Google acquired YouTube] it has put in place a growing number of technical measures to restrict competing search engines from properly accessing it for their search results," he said.
"Without proper access to YouTube, Bing and other search engines cannot stand with Google on an equal footing in returning search results with links to YouTube videos and that, of course, drives more users away from competitors and to Google."
Smith added that this practice extends to the mobile space, with Google preventing Windows Phone 7 users accessing YouTube in the same way as iPhone and other handset users.
"In 2010 Google blocked Windows Phones from operating properly with YouTube. Google has enabled its own Android phones to access YouTube [and] done the same for iPhones offered by Apple, which doesn't offer a competing search service," he said.
"Microsoft is ready to release a high quality YouTube app for Windows Phone. We just need permission to access YouTube in the way that other phones already do, permission Google has refused to provide."
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