Court filings show that 11 states attorneys general joined the lawsuit, while the DoJ said it has asked for 'structural relief as needed to cure any anticompetitive harm' in what may be the biggest U.S monopoly case in more than two decades.
The DoJ said the action was brought to "restrain Google from unlawfully maintaining monopolies in the markets for general search services, search advertising, and general search text advertising in the United States through anticompetitive and exclusionary practices, and to remedy the effects of this conduct."
Google said the suit was "deeply flawed", arguing that "people use Google because they choose to -- not because they're forced to or because they can't find alternatives" and adding it would have a fuller statement later Tuesday.
Google shares were marked 0.8% higher in early trading Tuesday to change hands at $1,542.44 each, a move that would extend the stock's six month gain to around 21% and bump its market value to just over $1.05 trillion.
A Congressional report published earlier this month accused the group of favoring its own products in search results, a similar charged levied by competition authorities in Europe, and noted 'concern' with Google's increasing market share gains in cloud computing.
Google also faces potential action from states attorneys general, lead by Texas AG Ken Paxton, that could focus on its search, advertising and android operating systems.
Last year, EU antitrust regulators fined Alphabet $1.7 billion for unfairly restricting rivals from displaying ads on its platform via third parties using its AdSense tool.
Regulators said Google abused its market dominance by restricting third-party websites, such as newspapers, blogs and travel aggregators, from placing ads from Google's rivals.
Google was also fined a record $5 billion by European antitrust authorities in 2018 following a lengthy investigation into contracts that tie makers of android-operated smartphones to the exclusive sale of its apps.
That decision followed a €2.4 billion levy from Brussels for denying "other companies the chance to compete on the merits and to innovate" in the market for price comparison searches on its website.