The US government was preparing to sue Google on Tuesday in what would be the biggest antitrust case in decades, media reports said.
The Wall Street Journal and New York Times said the Justice Department suit will accuse the California tech giant of illegal monopoly behaviour to preserve its dominance in internet search and advertising.
The move comes after months of investigations by federal and state antitrust enforcers seeking to check the power of the massive technology firm and parallel probes into other giants such as Amazon, Facebook and Apple.
It was not immediately clear what remedy the government was seeking in the suit, which could take years to resolve. But it could force changes in business practices or break off segments of the Google empire.
The Justice Department had no immediate comment but scheduled a briefing for media later Tuesday. Google did not immediately respond to an AFP request for comment.
