Microsoft in fresh attack against Google Microsoft opened a fresh front in its legal battle with Google, lodging a complaint with Europe's competition watchdog over Motorola Mobility, the smartphone maker and Google takeover target, alleging it is shutting out rivals through aggressive patent enforcement. The latest foray in the smartphone industry's patent wars on Wednesday comes amid growing official concern in Brussels over companies stifling competition by exploiting patents that are used in industry standards. Microsoft claims that Motorola effectively attempted to "block sales" of its products by overcharging for essential patents that it promised to license on a fair basis to all-comers. If a patent is included in an industry standard, companies are required to license them on "fair, reasonable and non-discriminatory" terms. The tenor of the Microsoft filing, which refers to patents used in video streaming and wireless technology, echoes a protest from Apple last week. Google brushed off the allegations, saying: "We haven't seen Microsoft's complaint but it's consistent with the way they use the regulatory process to attack competitors. It is particularly ironic given their track record in this area and collaboration with patent trolls. The complaints hope to nudge the Commission into acting on concerns it has already expressed over patents being used to abuse market power. Regulators on both sides of the Atlantic last week cleared Google's $12.5bn acquisition of Motorola, while expressing reservations about the potential use of the smartphone maker's arsenal of roughly 17,000 patents to bully rivals. Brussels last month opened an investigation against Samsung Electronics over concerns that it breached antitrust rules with a barrage of lawsuits blocking rivals" access to key technologies. After the Google merger decision, Joaquín Almunia, competition commissioner, said he would "continue to keep a close eye on the behaviour of all market players in the sector, particularly the increasingly strategic use of patents." The uncompromising tactics in the patent wars have manifested in a slew of lawsuits and a wave of acquisitions of big patent portfolios such as those owned by Motorola and Nortel, the bankrupt Canadian telecoms equipment maker. The Commission said: "We have received a complaint and will examine it." Microsoft said: "We have taken this step because Motorola is attempting to block sales of Windows PCs, our Xbox game console and other products." This marks the second complaint this year filed against Google by Microsoft, a tech giant that was once the arch foe of Brussels. Partly in response to pressure from the Commission during the merger approval process, Google made a public declaration of how it intended to use Motorola patents, detailing a 2.25 per cent ceiling to its royalties and steps it would take to resolve disputes before resorting to court. Microsoft and Apple argue Google's commitments fall well short of their own promises to never seek a court order to block the use of standard essential patents.