BERLIN- German companies managed to attract more apprentices to on-the-job training schemes last year due to a surge in applications from asylum seekers from Afghanistan and Syria, data showed on Wednesday.

The findings could be a boon for Chancellor Angela Merkel who has faced strong criticism from the far-right, anti-immigration Alternative for Germany (AfD) party as she has defended her decision to allow in more than one million migrants since 2015, many refugees from war zones.

Shortages of skilled labour and a lack of young people willing to commit to on-the-job training for up to 3-1/2 years have become big concerns for managers in Europe's largest economy.

Vacancies for training positions have reached their highest level in more than 20 years with more than a third of companies unable to fill all of their training spots.

However, the high number of asylum seekers has helped to ease the problem, data from the Federal Statistics Office showed on Wednesday.

The number of new trainees with no German citizenship rose by 10,500, helping to lift the overall number of new vocational training contracts by 5,700 to 515,700 in 2017, the data showed.

Interest was particularly strong among young men from Afghanistan and Syria as their number among the new apprentices more than tripled, the office said. Without their applications, German companies would have ended up with fewer new trainees.

Merkel has argued in the past that Germany's ageing society could also benefit from the humanitarian decision to help refugees.

"The numbers of young refugees who started on-the-job training increased significantly. That's good news, and it underpins (that) integration through education can succeed," the head of the BDA employers association, Steffen Kampeter, said.

Kampeter urged asylum authorities in Germany's 16 federal states to implement nationally agreed integration rules more consistently in order to provide as much planning security as possible for companies and refugees alike.

Since August 2016, asylum seekers can continue on-the-job training over three years and work for another two years under certain conditions even if their asylum requests were rejected.

This so-called 3+2 rule is meant to facilitate integration and to reduce the risks for companies that they lose a skilled worker after having invested in his or her training.

"Without reliability at this point, there's an increased risk of dropouts which could frustrate businesses and reduce their willingness to offer training to refugees," Achim Dercks from the DIHK Chambers of Industry and Commerce said.

Germany's dual-track training system, which also includes theory lessons at vocational schools, is being exported in various forms to Europe, Asia, Africa and the United States. But its popularity is waning at home as young people increasingly prefer the higher status of a university degree.

That could hurt growth in Europe's biggest economy by exacerbating a skilled labour shortage, which is partly caused by hundreds of thousands of ageing employees leaving the labour market every year.

The statistics office said that the number of dropouts in vocational training fell slightly last year as roughly 146,000 training contracts were terminated prematurely.

(Reporting by Michael Nienaber Additional reporting by Holger Hansen Editing by Alexander Hudson, Richard Balmforth) ((michael.nienaber@thomsonreuters.com; +49 30 2888 5085; Reuters Messaging: michael.nienaber.reuters.com@reuters.net www.twitter.com/REUTERS_DE www.reuters.de))