Tech giant Google has lodged an appeal against the 2.4bn euro fine (£2bn / $2.8bn) it was ordered to pay by the European Commission in June.
The regulator had ruled that positioning its own shopping comparison service at the top of Google search results was an abuse of power.
The fine was the largest penalty ever issued by the regulator, which also said the firm could face more fines if it continued its practices.
Google said it had no further comment.
At the time that the fine was imposed, Margrethe Vestager, the European Union’s Competition Commissioner said that Google’s activity was “illegal under EU antitrust rules”.
A spokesman then said that Google “respectfully disagreed” with the ruling.
Google was also given 90 days to end the “anti competitive” practices or face a further fine amounting to 5% of the average daily global earning of its parent company Alphabet.
The deadline for making the changes is 28 September.
Google appeals against huge EU anti-trust fine