Google’s planned acquisition of Motorola Mobility, one of the biggest mobile stories of the year, has taken another step forward with the announcement that it’s being scrutinised by the European Commission.

As Reuters reports, the Commission will make a decision on the $12.5 billion deal by 10 January 2012.

With acquisitions as significant as this, regulatory approval is a common hurdle, especially when it has huge potential implications for the Android ecosystem and the mobile market as a whole. Google plans to swallow up one of the biggest names in the mobile handset business, which would increase its influence on the market to greater levels.

A year ago, the European Commission launched an antitrust investigation into Google’s treatment of competitors in markets such as search, mapping and news. It could result in a signifcant fine for Google if it is found to have acted in an anti-competitive way.

Although this is completely separate to the Motorola deal, it does mean that the Brussels-based executive arm of the European Union currently holds plenty of power over how Google’s 2012 will shape up.