Google must sell its Chrome browser to restore competition in the online search market it dominates, and take a broad range of other corrective actions, including sharing data and search results with competitors, US prosecutors argued to a judge.
Such changes would essentially result in Google being highly regulated for 10 years, subjecting it to oversight by the same Washington, DC, federal court that ruled the company maintained an illegal monopoly in online search and related advertising.
Google, which is owned by Alphabet, controls about 90 per cent of the online search market and 95 per cent on smartphones.
Court papers filed on Wednesday night expand on an earlier outline for what prosecutors argued would dilute that monopoly.
Google called the proposals radical at the time, saying they would harm US consumers and businesses and shake American competitiveness in AI.
The company has said it will appeal.
The US Department of Justice and a coalition of states want US District Judge Amit Mehta to end exclusive agreements in which Google pays billions of dollars annually to Apple and other device vendors to be the default search engine on their tablets and smartphones.
Google will have a chance to present its own proposals in December.
Mehta has scheduled a trial on the proposals for April, though President-elect Donald Trump and the department's next antitrust head could step in and change course in the case.