BERLIN — A judge in Frankfurt dealt a setback to Uber on Wednesday, ruling that drivers for its ride-sharing service UberPop must hold the official permits required of taxi drivers to operate in Germany. The ruling reinstates one of the most severe legal restrictions faced by the company anywhere in the world.

The decision, by Judge Joachim Nickel, overturns a ruling from September that allowed UberPop to operate. The injunction against the service was sought last year by a taxi drivers’ trade group.

Uber operates two other services in Germany and elsewhere in Europe — UberBlack and UberTaxi — that use only professionally licensed drivers. Those services are not affected by Wednesday’s ruling, which also ordered that Uber be fined 250,000 euros, or about $270,000, for each violation.

Uber’s services allow drivers to connect with potential passengers using a smartphone app, offering passengers rides for prices well below those of Germany’s highly regulated taxis. But the company, based in San Francisco, has faced legal challenges across the world, especially in Europe, since it was founded in 2009.