European Union regulators fined Google more than $5 billion on Wednesday for abusing the dominance of its Android operating system, and said the tech giant should look to make competition more fair.

The EU is calling for Google to allow smaller players in the mobile operating system space to flourish in the marketplace, a source familiar with the matter told the Wall Street Journal .

Android OS is the world’s most popular mobile software system, running on more than 80 percent of smartphones globally.

Phones with the Android OS come preloaded with Google apps and services for email, search, music, maps, videos, and the like. Competitors have complained that this gives Google an unfair advantage in attracting users to those apps. The EU's opinion specifically implies that more people would use MIcrosoft's Bing search engine if Google did not require or provide financial incentives for manufacturers to sell their devices preloaded with Google's own search engine.

The EU also claims that through the preloaded apps, Google also gains an advantage in being able to collected and use data from a higher number of users in selling targeted advertising.

The EU alleged that Google acted illegally when it leveraged its market power to get makers of phones that utilize Android OS to pre-install these apps on the devices.