* New car registrations rise 19.4 percent in April
* Jan-April sales best since record high in 1999
* Government incentive scheme fuels demand
* European car sector index rises 1.3 percent
(Adds quote, details from other countries)
FRANKFURT, May 5 (Reuters) - New car registrations in Germany, Europe's biggest auto market, rose 19.4 percent to nearly 380,000 vehicles in April as motorists continued to cash in on government incentives to junk old cars and buy new ones.
That brought new car sales in the first four months of the year to the best level since the record year of 1999 even as demand plummets in other major markets, data compiled by the VDIK car importers association showed on Tuesday.
"The Environmental Bonus is a complete success and justifies its name," VDIK President Volker Lange said.
He noted that the average carbon dioxide (CO2) emissions from new cars registered in the first quarter were down around 6.5 percent year on year, which directly reflects a corresponding cut in fuel consumption typically.
The Berlin government launched in February a subsidy that pays motorists 2,500 euros ($3,310) to scrap cars at least nine years old if they buy a new model from any automaker in exchange.
The scheme has been so popular that the government has agreed to increase it to 5 billion euros from the 1.5 billion first envisioned. It runs until the end of this year.
The incentive has fuelled sales of small cars in particular but has drawn complaints from German retailers that it is sucking demand away from other businesses and prompted criticism it is a political gimmick ahead of September elections
VDIK said orders on hand showed the German market was set to keep growing briskly in the months ahead.
The DJ Stoxx European car sector index rose 1.7 percent by 1057 GMT, outpacing the broader market.
The government giveaways have made Germany one of the few bright spots for global car sales this year even though other countries such as France and Italy have adopted similar steps.
The U.S. market shrank by more than a third last month, while sales in Spain plunged nearly 46 percent.
New car sales in France fell 7 percent, and Italy's sales sank 7.5 percent as supplies of some models that include less polluting cars lagged an increase in demand fuelled by state incentives.
The British government last month announced plans to give motorists a 2,000 pound ($3,018) discount on purchasing a new vehicle when they trade in one more than 10 years old.
But the head of the country's biggest car retailer, Pendragon, told Reuters last week he thought the scheme would have "very little if any" impact because it was not big enough to change consumer behaviour.
Germany's scheme has largely passed by makers of big, expensive cars like Mercedes-Benz and BMW, but it has had a spillover effect in neighbouring Poland.
Analysts estimate that at least one out of every 10 new vehicles sold in Poland is driven by a German, where the zloty currency's retreat against the euro since last summer has made purchases there up to a third cheaper in euro terms. (Reporting by Michael Shields)