The European Union's top court dismissed an appeal on Thursday from the United States technology company Google against a 4.34-billion-euro ($4.95 billion) antitrust fine, setting up a likely protracted dispute between Brussels and Washington.

The decision not to overturn the record-breaking fine that EU regulators imposed eight years ago for Google's use of its Android mobile operating system to block rivals means the US could now respond with heavy financial penalties of its own. US President Donald Trump threatened last week to impose 100 percent tariffs on the bloc if such fines were levied against US technology giants.

The 4.34-billion-euro fine was reduced by a tribunal in 2022 to 4.1 billion euros, but will not be changed further, the Luxembourg-based Court of Justice of the European Union said.

"The appeal brought by Google and its parent company Alphabet against the judgment of the General Court is dismissed, thereby confirming the penalty imposed for Google Search's abuse of a dominant position in the context of the Android operating system," the ruling said.

Reuters said the ruling will strengthen the EU's arm in its ongoing crackdown against US Big Tech companies for what the bloc sees as unfair antitrust practices.