(Adds details, company comments)
BRUSSELS, Feb 15 (Reuters) - Europe's justice commissioner told Facebook, Twitter and Google on Thursday to do more to bring their user terms in line with EU law, ramping up pressure on the tech giants after their efforts were deemed too little.
The European Union executive and consumer protection authorities said the three companies have only partially addressed concerns about their liability and how users were informed about content removal or contract terminations.
The authorities across the bloc, who requested the changes last year, have the power to fine the firms if they do not comply.
European Commissioner Vera Jourova said the use of social media networks as advertising and commercial platforms meant they faced the same rules as offline service providers.
"EU consumer rules should be respected and if companies don't comply, they should face sanctions," Jourova said in a statement. "Some companies are now making their platforms safer for consumers; however, it is unacceptable that this is still not complete and it is taking so much time."
Facebook said it had worked with EU authorities to make changes to its terms and to ensure greater transparency. It said further updates of the terms were planned later this year.
"We have long had tools in place to inform people about content removals and intend to expand these tools later this year," a Facebook spokeswoman said.
A Google spokesman declined to comment and Twitter did not immediately respond to a request for comment.
The Commission said the U.S. trio had agreed to amend some terms that limit their liability, waive a users right to withdraw from online purchases and force European consumers to seek redress in California, where the firms are based, instead of the consumer's home country.
They have also agreed to change terms that release the social media firms from the duty of identifying commercial and sponsored content, the Commission said.
U.S. technology companies have faced tight scrutiny in Europe for the way they do business, from privacy issues to how quickly they remove illegal or threatening content.
The Commission said national authorities would monitor the implementation of changes made, make use of the procedures offered by the companies to handle illegal content and "may take action including enforcement measures where necessary."
Reporting by Alissa de Carbonnel @AdeCar; Additional reporting by Robert-Jan Bartunek