* March sales up 11.4 pct to 360,000 cars - KBA
* Q1 sales up 6.7 pct to 845,000 cars - KBA
* But April sales may shrink on fewer selling days - source (Releads on official data, adds analyst comment)
By Andreas Cremer
BERLIN, April 4 (Reuters) - Sales of new cars in Germany saw the biggest jump in almost a year in March, helped by two more selling days than in the same month last year and echoing signs of strong growth in other major European auto markets.
Registrations of new passenger cars in Europe's largest vehicle market increased 11.4 percent year-on-year to 360,000 autos last month, Germany's KBA vehicle authority said on Tuesday, confirming a Reuters story.
That's the biggest monthly gain since May 2016 when German registrations jumped 11.9 percent, according to KBA records. Adjusted for the two extra selling days, March sales rose about 2 percent, analysts said.
"Underlying conditions are still favourable and it's mainly private consumers who are currently driving demand in Germany," said Peter Fuss, a senior partner and automotive specialist in Ernst & Young's (EY) German practice, citing low unemployment and interest rates as well as good economic prospects.
First-quarter sales in Germany were up 6.7 percent to 845,000 vehicles, helped by a total of three additional selling days.
But registrations in April look set to shrink again as the long Easter weekend will reduce the number of selling days by two, an industry source said.
The share of Volkswagen group brands including luxury divisions Audi and Porsche fell to 35.1 percent of German sales from 38.5 percent a year ago, while BMW and its Mini brand slipped to 9 percent from 9.3 percent, according to EY calculations. Daimler's Mercedes and Smart brands rose to 9.6 percent from 9.4 percent.
Diesel models' share of new car registrations kept falling in March to 40.6 percent from 47.2 percent, Fuss said, as municipalities in Germany discuss tighter regulation to help tackle pollution.
Strong sales in Germany chime with double-digit gains in March already reported in Italy and Spain, Europe's fourth and fifth biggest markets respectively in 2016. (Editing by Maria Sheahan and Mark Potter)