The Federal Cartel Office, or Bundeskartellamt, last year determined Facebook was exploiting its dominance in social media to force users to share data from other Facebook-owned services like WhatsApp and Instagram, as well as third-party websites through the "Like" and "Share" buttons.
It gave Facebook several months to stop collecting data and combining it with Facebook users' accounts without their consent.
Facebook appealed that decision, and a Duesseldorf court ruled it did not have to comply with the regulations until the case had been decided.
In its decision Tuesday, the Federal Court of Justice in Karlsruhe overturned that decision, agreeing with the Cartel Office that Facebook's terms of use leave "private Facebook users with no choice" and said the company had to comply with the regulators.
"There are no serious doubts about Facebook's dominant position in the German social media network market, or that Facebook is abusing its dominant position with the terms of use prohibited by the Federal Cartel Office," the court said.
Facebook said the decision would not mean any immediate changes for people or businesses who use its products and services in Germany. It noted the main appeal is still pending.
"Today's decision relates to the preliminary proceedings on the court's stay order," the company said in a statement to The Associated Press. "The main proceedings, before the court of appeals, are ongoing and we will continue to defend our position that there is no antitrust abuse." (AP) MRJ