WASHINGTON D.C.: U.S. government regulators are taking aim at Google's search engine, which has become the internet's primary search platform.

The legal battle, which started this week in a Washington D.C. federal courtroom and is presided over by U.S. District Judge Amit Mehta, will be the most prominent US antitrust trial since regulators took action against Microsoft and its dominance of personal computer software some 25 years ago.

The 10-week trial is expected to witness testimony from leading executives at Google and corporate parent Alphabet, and other major technology companies, including Alphabet CEO Sundar Pichai, who succeeded Google co-founder Larry Page in 2019, and one of Apple's highest-ranking executives, Eddy Cue.

Before the end of its first phase, the trial is scheduled to continue into late November, followed by another round of court filings and arguments.

However, Judge Mehta is not expected to issue a ruling until early 2024. If he decides that Google has broken the law, another trial will be held to determine what measures should be taken against the Silicon Valley company, which is based in Mountain View, California.

Nearly three years after filing its antitrust lawsuit during the Trump administration, lawyers from the U.S. Justice Department have accused Google of abusing the power of its search engine to stifle competition in a manner that discouraged innovation.

As Google uses its engine to sell advertisements and promote its own products, critics also claim that the quality of search results has deteriorated.

During the trial, several state attorneys general, led by Colorado, will have a chance to prove that Google has become an illegal monopoly harming consumers.

In response, Google stressed that consumers could easily switch their default settings to another search engine.