Alphabet unit Google faces damages claims for up to €25 billion over its digital advertising practices in two suits filed in British and Dutch courts in the coming weeks by a law firm on behalf of publishers.
Google's adtech has recently drawn scrutiny from competition regulators following complaints from publishers.
The French competition watchdog imposed a €220m fine on the company last year.
The European Commission and its UK peer are also investigating whether Google's adtech business gives it an unfair advantage over rivals and advertisers.
"It is time that Google owns up to its responsibilities and pays back the damages it has caused to this important industry, Damien Geradin at law firm Geradin Partners said in a statement.
"That is why today we are announcing these actions across two jurisdictions to obtain compensation for EU and UK publishers," he added.
The British claim at the UK Competition Appeal Tribunal will seek to recover compensation for lost revenue from the sale of advertising space on the websites of news publishers and any site funded by online advertising.
The Dutch claim is open to publishers affected by Google's actions. Litigation funder Harbour is funding both lawsuits.
