Microsoft, the world's largest software maker, has filed its first ever complaint to antitrust regulators, claiming Google thwarts Internet search competition.

The Redmond-Wash. based company, which itself was prosecuted by the United States in the '90s and later by the EU for antitrust practices,  is now turning its aim at the largest Internet company.

Google controls over 90 percent of the Internet search advertising market in Europe, well ahead of Microsoft's Bing.

And Web browsers such as Firefox and Google's Chrome have eaten away at the market lead by Microsoft's Internet Explorer.

Microsoft chief counsel Brad Smith cited several examples of what his company claims are Google's unfair business practices in a official company blog.

The most damaging of these claims is that Google uses its ownership of YouTube to disadvantage competitors' search results.

Microsoft says that Google has put in place technical measures that restrict Bing search and other rivals, from properly accessing YouTube for their search results.

It claims Google uses that otherwise restricted data to index YouTube videos in its own search results.

Google is already under investigation by the European Commission after other complaints arose, one of them owned by Microsoft.

Google indicated it was not overly concerned by the complaint.

We're not surprised that Microsoft has done this, since one of their subsidiaries was one of the original complainants, a Google spokesman told Reuters.

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.