The recall process is now viable “technically, financially and in terms of manpower. This is good news,” chief executive Matthias Müller said.

“For over 90 percent of the Europe group's vehicles, solutions are now confirmed,” he told around a thousand VW executives at the company's headquarters in Wolfsburg, northern Germany, without giving more detailed figures.

The carmaker has admitted to fitting 11 million diesel engines worldwide with sophisticated software fitted to skew the results of tests for nitrogen oxide emissions.

That admission has triggered both regulatory and criminal investigations in several countries, including Germany and the United States.

Volkswagen has subsequently revealed that beyond the nitrogen oxide scam, it had also understated carbon dioxide emissions of 800,000 vehicles, including petrol cars.

The carmaker, whose divisions include Audi, SEAT and Skoda as well as its truck and commercial vehicles, now faces the sizeable task of recalling 8.5 million vehicles throughout Europe.

Müller has promised that the company would submit its recall plans to German authorities by the end of November.

The fixes will range from simple software update for two-litre diesel engines, to more complex solutions for 1.6-litre models.

Müller said VW's internal enquiry into the scandal was “very complex” and would take many months to complete, though he promised a report on its progress in mid-December.

“Our main concern is not sales figures or operating results. Our main concern is the credibility and confidence in our brands,” he added.

Volkswagen car sales fell 5.3 percent in October as the pollution cheating storm hit European demand.

Deliveries slipped 1.3 percent in western Europe compared to a year ago, with weakening demand seen in Germany, Spain and Italy.

Global sales were however lifted by its biggest market China, where deliveries rose 1.8 percent to 233,500 cars for the month.

Audi repairs to cost €50 million 

Audi said Monday it will spend about 50 million euros upgrading software that regulators believe flouts US pollution limits in larger diesel cars in the US.

The upscale brand of Volkswagen said the repairs will cover auxiliary emission control devices (AECD) for V6 diesel 3.0-liter cars that the Environmental Protection Agency has since early November alleged violate US emissions laws.

Audi “estimates that the related expense will be in the mid-double-digit millions of euros,” the company said in a news release.

EPA said Friday that Audi had told US regulators that three-liter diesel models since 2009 contain the AECD.

The US agency alleges that the AECD permitted Audi to evade US emissions controls.

Audi maintains that the system was not devised to evade the emissions limits, but to redirect gases in order to reduce emissions of carbon dioxide.

However, Audi has admitted that it did not disclose the AECDs as required under US law.

The models affected are the A6, A7, A8, Q5 and Q7. The problem affects about 85,000 Audi, Porsche and Volkswagen vehicles in the United States.