Google’s proposed US$12.5 billion acquisition of Motorola Mobility has been approved by Chinese authorities, paving the way for full completion of the deal, reports Reuters.

The deal was approved by US and European regulators in February, meaning it has now passed all regulatory hurdles for it to take place. Google and Motorola have been waiting for approval from China for several months after the Chinese authorities extended an investigation into the acquisition.

The planned merger – first announced in August 2011 – will allow Google to secure valuable patents held by Motorola and combine the Android OS with Motorola devices. Android is the most widely used smartphone OS and Google is hoping Motorola’s patents – of which there are 17,000 – will boost its efforts to compete with Apple and protect other Android phone makers from patent litigation.

A major condition of the Chinese approval is that Android remains free and open for five years, according to a Reuters source. A Motorola spokeswoman added that the company hopes to close the deal early next week.

In related news, several Motorola smartphones have been found by the US International Trade Commission (ITC) to infringe a Microsoft-held patent and are banned from import into the country. US President Barack Obama now has 60 days to decide whether to overturn the ruling.

The Microsoft patent in question is for technology that allows users to generate and schedule meeting requests using their mobile devices. Microsoft has requested Motorola devices, including the Atrix, Backflip, Droid 2 smartphones and the Xoom tablet, be stopped at the US border. Motorola said it was disappointed with the ruling but will “explore all options including appeal.” 

Microsoft first filed a complaint with the ITC in October 2010, accusing Motorola of infringing nine of its patents for Windows Mobile and Windows Phone.