EU Competition Commissioner Margrethe Vestager is due to give a press conference at 1 pm (1100 GMT), at which she is expected to announce the decision following a three-year investigation.
The commission has accused Google of hindering competition and reinforcing its dominant position among search engines by forcing manufacturers to pre-install its search engine and Chrome web browser on Android devices in order to use any of its licensed apps - such as the popular Google Play app store.
Android is the world's most-used smartphone operating system and runs on about 80 per cent of mobile devices worldwide. The open-source software is provided to manufacturers free of charge, while Google derives revenue from advertising displayed in its apps.
Google has rejected the EU's accusations, arguing that its approach encourages competition.
Wednesday's penalty will outstrip a previous record fine of 2.42 billion euros that the EU's competition watchdog imposed on Google last year for boosting its own shopping service in online search results.
These are the top two highest antitrust fines the commission has imposed on an individual company, followed by a 1.06-billion-dollar fine on chip manufacturer Intel in 2009.
Google has appealed the penalty issued for its Google Shopping service before the European Court of Justice and is likely to take legal action against Wednesday's decision too.
The commission has accused Google of hindering competition and reinforcing its dominant position among search engines by forcing manufacturers to pre-install its search engine and Chrome web browser on Android devices in order to use any of its licensed apps - such as the popular Google Play app store.
Android is the world's most-used smartphone operating system and runs on about 80 per cent of mobile devices worldwide. The open-source software is provided to manufacturers free of charge, while Google derives revenue from advertising displayed in its apps.
Google has rejected the EU's accusations, arguing that its approach encourages competition.
Wednesday's penalty will outstrip a previous record fine of 2.42 billion euros that the EU's competition watchdog imposed on Google last year for boosting its own shopping service in online search results.
These are the top two highest antitrust fines the commission has imposed on an individual company, followed by a 1.06-billion-dollar fine on chip manufacturer Intel in 2009.
Google has appealed the penalty issued for its Google Shopping service before the European Court of Justice and is likely to take legal action against Wednesday's decision too.