Demand for vehicles to be fitted with diesel particulate filters is increasing, amidst health concerns over diesels' impact on air quality.

German manufacturers are said to be rushing to offer particulate filters as standard or optional equipment, Reuters reports.

Volkswagen has said it will be offering the products by autumn this year, while Mercedes-Benz already offers 20 diesel models with filters.

"We have to take this topic seriously," Volkswagen marketing chief Georg Flandorfer told industry paper Automobilwoche, Reuters reports.

"Dealers have told me there is a lot of customer interest to have particle filters retrofitted. We should concentrate on retrofit solutions for now because that does the most for the environment," he added.

The German government is trying to accelerate the introduction of diesel engine particle filters after Munich and Stuttgart went over new EU air pollution limits only a few weeks after they came into force this year.

The Frankfurter Allgemeine reports that the government received the surprise backing last week of the states' transportation ministers for a proposal to give tax breaks to drivers using the filters.

Officials have suggested that a new law could be proposed before the summer.