After Apple, it is Microsoft which has accused Google of patent misuse. Microsoft has accused the search engine giant of misusing standard essential patents to gain supremacy in the mobile phone market. Microsoft has sought the aid of European regulators to investigate the alleged unfair use of patents.

The escalating legal war on patents and infringements has sparked a debate: are some companies exploiting a patent to unfair advantage to curb the competition in the lucrative smartphone market?

In the latest round, Microsoft has accused Motorola (its mobile arm was recently acquired by Google) of violating technology industry agreements concerning the fair usage policy of patent acquisitions, licensing prices (royalty) and terms.

The Windows software major has complained to the European Commission that Motorola is overcharging device makers to use standard patents for simple tasks such as enabling people to view videos on the Web and connect wirelessly to the Internet, according to the Wall Street Journal.

As a result of the alleged unfair licensing policies of Motorola, Microsoft's laptops and Xbox game consoles have reportedly been affected.

European regulators are already investigating if Samsung Electronics Co. is misusing any of its patent rights against its competitors. The Korean smartphone giant has vowed to fight back the authority's investigative actions, as it wasn't prompted by any of the legal opponents in its ensuing patent wars.

Google has refuted Microsoft's complaint saying that "it is just another example of their attempts to use the regulatory process to attack competitors," reports the Wall Street Journal.

Motorola too has denied Microsoft's claims of patent misuse and that it had made fair offers to the company which were ignored earlier.

Microsoft's allegations seem to have come in the wake of Google's $12.5 billion acquisition of Motorola Mobility Holdings only recently. The software giant must be perturbed with the culmination of Google's threatening portfolio that could land the former in deep trouble amidst escalating patent countersuits.

The latest survey results from comScore Inc. suggest Android's domination in the U.S. smartphone market with a net share of 47.3 per cent, which currently exceeds the combined market share of Apple and Research in Motion Ltd.

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