The European Commission (EC) is reportedly investigating Google over claims that the company used anti competitive methods to increase sales of its Android operating system (OS).
According to documents seen by the Financial Times, the EC has focused on allegedly anti-competitive agreements signed between Google and smartphone providers.
The news agency said the informal investigation is at a preliminary stage and follows recent complaints by Microsoft and Nokia.
The watchdog will also be probing on whether the US-based Google is forcing manufacturers to pre-install and place its own apps like YouTube and others.
Google said: "Android is an open platform that fosters competition. Handset makers, carriers and consumers can decide how to use Android, including which applications they want to use."
A recent report from International Data Corporation has revealed that Google’s Android and Apple’s iOS OS powered 92.3% of all smartphones shipped during the first quarter of 2013.
EC is also investigating Google’s alleged misuse of dominant position in the online search market since 2010.
In April this year, Google submitted a package of concessions to the European Union (EU) to resolve antitrust investigations.