Volkswagen saw its market share in Europe drop fractionally in September, when its emissions scandal broke mid-month, as its sales growth lagged behind the wider market.

VW Group sales, comprising all brands, rose by 8.4 per cent in the European Union, according to regional car makers association the ACEA. The mass-market VW brand most implicated in the scandal, saw sales rise 6.6 per cent.

That compared with an overall increase in car registrations of nearly 10 per cent to 1.35 million units across the region.

The VW Group, which eclipsed Toyota in the first half of the year to become the world's top-selling car maker, saw its European market share dip to 23.3 per cent from 23.6 per cent in September 2014. Last September, its sales growth exceeded the market.

Volkswagen still remains by far the dominant car maker in Europe, well-ahead of second-place PSA Peugeot Citroen with 10 per cent of the market.

Volkswagen's emissions scandal broke in mid-September, when US authorities revealed software that disabled emissions controls except when they were being tested. The company said there are a total of 11 million cars with such software, 8.5 million of which are in Europe.

Because of the timing of the scandal, any impact on demand for Volkswagen cars would not be reflected entirely in the September sales data.

Some European countries have suspended the sale of Volkswagen diesel models that contain the cheating software, pending a fix from the company.

German authorities have ordered a recall of all VW cars fitted with the software, affecting all 8.5 million diesel cars across the EU. The company said a fix could stretch through 2016.

September's rise in EU car sales was the 25th straight monthly increase. While growth this year has been strong, the ACEA noted the European market is still far below pre-crisis levels.