A judge on Monday dismissed a blockbuster antitrust suit against Facebook filed last year by federal and state regulators, saying the lawsuit failed to "plausibly" establish that the social network had created a monopoly.

Judge James Boasberg of the US District Court of Washington DC dismissed the case filed in December by the Federal Trade Commission and more than 40 states, which could have rolled back Facebook's acquisition of Instagram and the messaging platform WhatsApp.

The lawsuit "failed to plead enough facts to plausibly establish a necessary element... that Facebook has monopoly power in the market for personal social networking services," the judge said in a 53-page opinion, while allowing authorities the opportunity to refile the case with revisions.

Facebook won dismissal of an antitrust suit filed by US federal and state regulators, as a judge ruled authorities failed to establish the social media giant was a monopoly
Facebook won dismissal of an antitrust suit filed by US federal and state regulators, as a judge ruled authorities failed to establish the social media giant was a monopoly AFP / OLIVIER DOULIERY

In lawsuits filed in December which were consolidated in federal court, US and state officials called for the divestment of Instagram and WhatsApp, arguing that Facebook had acted to "entrench and maintain its monopoly to deny consumers the benefits of competition."

But the judge said the complaint "says almost nothing concrete on the key question of how much power Facebook actually had... it is almost as if the agency expects the court to simply nod to the conventional wisdom that Facebook is a monopolist."

Facebook shares surged after the decision, lifting the company's valuation above $1 trillion for the first time.

The move comes a week after a US congressional panel advanced legislation which would lead to a sweeping overhaul of antitrust laws and give more power to regulators to break up large tech firms.