BERLIN (Reuters) - The number of births in Germany fell to a record post-war low last year despite government investment of billions of euros on incentives to counter the country’s shrinking population.

Germany has a population of 82 million but the low birth rates mean average ages are rising, hampering the development of Europe’s largest economy. The tide of immigration that fed the post world war two economic expansion has also now been reversed with new immigration controls.

The Federal Statistics Office in Wiesbaden reported that there were 665,126 children born in 2009, down from 682,514 in 2008. The annual birth rate has fallen by more than 100,000 a year in the last decade from 770,774 births registered in 1999.

An official at the statistics office said the 2009 figure was the lowest number of births in Germany since 1945, when 520,000 children were born.

Germany has one of the lowest birth rates in Europe.

Demography experts have forecast that Germany’s population could fall from 82 million to about 50 million by 2050 while countries with growing populations, such as France and Britain, could overtake it later this century.

The government introduced an “Elterngeld” (parent money) benefit in 2007 worth up to 25,000 euros a year to encourage working couples to have children. That programme costs taxpayers more than 3.5 billion euros ($4.77 billion) per year.

The number of births rose by 10 percent to 684,862 in 2007 from 2006 but the number has since resumed its downtrend.

The record number of births was in 1964, when a total of 1,357,304 children were born in East and West Germany.

On top of the “Elterngeld,” the government spends another 2.5 billion euros each year on “Kindergeld,” or monthly support payments to all families in Germany with children.

Germany’s falling birthrate and shrinking population have alarmed policymakers for decades.