Google sought to play down its anti-trust battle with the European Commission on Friday, with a senior executive insisting the row was "normal".

Brussels has charged Google with abusing the dominance of its Android mobile phone operating system in a move which could could change the face of the global smartphone sector.

But Carlo d'Asaro Biondo, Google's Europe head of strategic partnerships, said he was unfazed by the investigation.

"We'll see where that leads. It's normal, given the importance Android has in Europe ... that the Commission undertakes controls," Biondo told reporters.

EU Competition Commissioner Margrethe Vestager says the Silicon Valley giant has used practices such as making manufacturers pre-install its market-leading search engine as the default in phones to "abuse its dominant position".

Brussels believes such practices breach EU competition law.

The Android operating system accounts for about 80 percent of the world market for mobile phones, far ahead of Google's closest rival, Apple.

The EU has accused Google of obstructing innovation by giving unfair prominence to its own apps, especially its search engine, in deals with mobile manufacturers such as Samsung and Huawei.

Google must now respond inside three months to avoid sanctions which could amount to fines up to 10 percent of the group's annual global sales or $7.4 billion based on their 2015 results.

Biondo said Google would now seek to put its own case. "We are in that phase and will see what happens," he told reporters.

"What we are trying to do today is explain what we are doing and what our system is. We are not at the sanctions phase, we are in the analysis phase," he added, indicating that Android allows several phone makers easier access to the market without having to develop their own operating systems.

He said the platform enabled a current estimated 1.2 million developers to work on applications in Europe and that the software was free for operators which they could use or not as they wished.

"Google Play is a magnificent way of distributing non Google applications," Biondo said.