WASHINGTON, Oct 9 —The US Department of Justice on Tuesday said it would demand that Google make profound changes to how it does business and even consider the possibility of a breakup, after the tech juggernaut was found to be running an illegal monopoly.

Determining how to address Google’s wrongs is the next stage of a landmark antitrust trial that saw the company in August judged a monopolist by US District Court Judge Amit Mehta.