* Diesel sales plunge 19 pct, 41 pct market share
* Four-month regs up 2.5 pct to 1.14 mln cars
* German drop echoes Italy, France declines, Spain rises (Adds KBA figures, analyst comment and background)
BERLIN, May 3 (Reuters) - New car sales in Germany declined 8 percent in April, with sales of diesel-powered vehicles dropping 19 percent as politicians debate imposing bans on diesel cars being driven in certain areas or refitting older engines with better emission controls to tackle pollution.
Registrations of new cars in Europe's largest auto market fell to 290,697 vehicles in April because of three fewer selling days, restricting the rise in sales in the first four months of the year to 2.5 percent, to 1.14 million cars, the KBA federal vehicle authority said on Wednesday, confirming an earlier report by Reuters.
Sales of diesel cars plunged, with their share of the overall market shrinking to 41 percent, KBA said, noting that sales of gasoline-powered cars were flat while electric vehicles posted strong gains from low base levels.
Stuttgart, home to premium carmakers Porsche and Mercedes-Benz, has been discussing banning diesel cars from the city centre, while ministers of Germany's regional governments are calling for older cars to be fitted with better emission controls.
"The market share of diesel cars will probably decline further in the coming months and years because the discussion about diesel vehicles and driving bans won't stop," Peter Fuss, a senior partner and automotive specialist in Ernst & Young's German practice, said on Wednesday.
Adjusted for three more selling days, car sales would have risen 7 percent last month, an industry source told Reuters, with demand seen from both private and commercial buyers.
Germany's sales drop mirrored declines in France and Italy whereas Spain reported a small increase. (Reporting by Andreas Cremer; Editing by Maria Sheahan, Greg Mahlich)