Barnes and Noble has asked the U.S. Department of Justice to look into Microsoft's patent licensing agreements with electronic devices running on Google's Android OS as anti-competitive.

In a presentation before the U.S. International Trade Commission, Barnes and Nobles asserts that Microsoft is trying to monopolize the market for modern operating systems by threatening devices that use Android software, reports Bloomberg.

"Microsoft's willingness to bully small players with expensive litigation raises a substantial barrier to entry in any market in which it claims dominance," B&N's general counsel, Eugene DeFelice, wrote in a March letter to the department's then-antitrust chief, Christine Varney.

"Microsoft's exorbitant licenses for its patents entrench the dominant players in the relevant markets because those players can afford to take a license, while small players cannot," DeFelice wrote.

The case being presented before the anti-trust division is a complaint filed by Microsoft against B&N for allegedly infringing on Microsoft's patents with its Nook e-reader and Nook Color tablets. Microsoft maintains that certain features in the Android operating system infringe on Microsoft's intellectual property rights.

Barnes and Noble filed a series of letters and presentations to defend itself against Microsoft's claims. In another letter, dated October 17 B&N described a licensing deal between Microsoft, Nokia and MOSAID technologies as another example of Microsoft edging out competitors running the Android operating system. In September, MOSAID acquired 2,000 wireless technology patents from Nokia. MOSAID, Nokia and Microsoft had entered into a revenue-sharing scheme that will give two-thirds of any revenue generated by licenses or lawsuits to Microsoft and Nokia.

"Android, which Google gives away for free, threatens Microsoft's traditional business model of licensing its proprietary operating system because OEMs [original equipment manufacturers] no longer need to pay for a high-quality operating system," said the letter written by Peter Barbur, an attorney at Cravath, Swaine and Moore to a DOJ official.

Barnes and Noble assert that these attacks on Android are a way for Microsoft to keep its desktop monopoly from the increasing popularity of tablets that run on the free Android operating system. A trial on Microsoft's patent infringement claim against B&N is set for Friday.

"All modern operating systems include many patented technologies. Microsoft has taken licenses to patents for Windows and we make our patents available on reasonable terms for other operating systems, like Android. We would be pleased to extend a license to Barnes & Noble," Microsoft said in a statement issued on Tuesday afternoon.