A Porsche Cayenne car is seen in the emission test centre of the University of Applied Sciences in Nidau, Switzerland November 27, 2015. Picture taken November 27, 2015. REUTERS/Ruben Sprich

ZURICH (Reuters) - Switzerland’s road agency on Friday imposed a preliminary ban on new registrations of Porsche Cayenne cars equipped with manipulated diesel engine management software.

The preliminary ban, imposed on Cayenne cars with three-litre diesel motors of emissions standard euro 6, does not affect cars already registered in Switzerland, the agency said.

Sports car maker Porsche AG is owned by Volkswagen VOWG_p.DE, which in 2015 admitted to systematic manipulation of engine management software to cheat emissions tests.

Germany in late July announced a recall of affected Porsche Cayenne models after finding potentially illegal emissions controlling software in the vehicles.

Germany must eventually follow other European countries in banning new diesel cars, Chancellor Angela Merkel has said, conceding for the first time that diesel’s days are numbered in the wake of the emissions scandals. Her comments followed mounting pressure on Germany’s auto makers who concealed from regulators the true emissions level of diesel vehicles.