BRUSSELS - Google lost most of the first round of its battle to topple a landmark 4.3 billion-euro (S$6.03 billion) European Union anti-trust fine that struck at the heart of the US tech giant's power over the Android mobile phone ecosystem.

EU judges mainly backed the European Commission's decision to impose the penalty, but cut it to 4.1 billion euros.

Google on Wednesday voiced disappointment with the EU court judgment.

“We are disappointed that the Court did not annul the decision in full. Android has created more choice for everyone, not less, and supports thousands of successful businesses in Europe and around the world,” the company said in an e-mail.

The Android case is one of a trio of decisions that have been the centrepiece of EU anti-trust chief Margrethe Vestager's bid to rein in the growing dominance of Silicon Valley.

She's fined Alphabet Inc's Google more than 8 billion euros and has since opened new probes into the company's suspected stranglehold over digital advertising.

Wednesday's ruling can now be appealed to the bloc's top court, the EU's Court of Justice.

The European Commission in its 2018 decision accused Google of three separate types of illegal behaviour that helped cement the dominance of its search engine.

First, it said Google was illegally forcing handset makers to pre-install the Google Search app and the Chrome browser as a condition for licensing its Play Store - the marketplace for Android apps.

Second, the EU said Google made payments to some large manufacturers and operators on condition that they exclusively pre-installed the Google Search app.

Lastly, the EU said the Mountain View, California-based company prevented manufacturers wishing to pre-install apps from running alternative versions of Android not approved by Google. BLOOMBERG, REUTERS