Diesel-powered cars' share of the German market continued its slide in March, according to official data, sapped by a court ruling that could see the vehicles banned from parts of city centres.

Just 31.4% of cars registered by the KBA federal vehicle licensing authority last month were diesels, 9.2 percentage points fewer than in March 2017.

Judges ruled in February that local authorities can ban diesel vehicles from the most polluted parts of city centres to reduce levels of harmful fine particles and nitrogen oxides (NOx) in the air.

The newly-installed federal government under Chancellor Angela Merkel is scrambling to ward off such bans, but in the meantime the threat alone, combined with plummeting resale values, have put buyers off.

Across the whole car sector, new registrations fell 3.4% year-on-year to 347,433 in March.

But over the first three months of the year, auto sales, a key indicator of health for Europe's largest economy, were up 4%.

The world's largest carmaker, Volkswagen, at the origin of the diesel scandal with its 2015 admission that it manipulated millions of cars to fool regulators' emissions tests, boosted German sales 7.2% in the first quarter.

High-end carmaker BMW, which along with VW was earlier this year dragged into an uproar over diesel emissions testing on monkeys, saw sales slip 1.9% in the first three months.

Meanwhile Mercedes-Benz, whose parent company Daimler was also linked to the primate research, increased sales slightly.