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

Google won more time Wednesday to answer accusations by the European Commission that the US tech giant abuses the dominance of its Android mobile phone operating system.

"The Commission has agreed to extend Google's deadline to respond to its Statement of Objections concerning Android and its applications until 7 September," a spokesman for the EU's executive arm told AFP.

The decision extends Google's deadline from July 27 and came on the day US Treasury Secretary Jacob Lew was to visit EU officials in Brussels, including EU Competition Commissioner Margrethe Vestager.

The many battles opened by Vestager against US companies on competition issues has put a strain on transatlantic ties.

Other EU investigations include cases against Starbucks, Amazon and McDonald's.

In the Android case, the commission has accused Google of obstructing innovation by giving unfair prominence to its own apps, especially its search engine, in deals with mobile phone manufacturers such as Samsung and Huawei.

Google's response will be the company's last chance 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.

The case is the second attack by the EU against Google after Vestager last year formally charged the company for abusing its dominance of the in Europe.

Google could also face a third wave of EU anti-competition charges, this time targeting the giant's advertising business.

Vestager's team is expected to close a long-running state-aid inquiry into Apple's tax arrangements in Ireland, which some have suggested could see the iPhone maker on the hook for $19 billion in back taxes.

Lew has repeatedly complained to Vestager that EU anti-trust regulators unfairly target US firms, a charge which the former Danish finance minister firmly denies.