Volkswagen announced plans today to refit up to 11 million vehicles and overhaul its namesake brand to try to move on from the scandal over its cheating on diesel emissions tests. 

New chief executive Matthias Mueller said the German carmaker would ask customers "in the next few days" to have diesel vehicles that contained illegal software refitted.

Analysts have said that such a move could cost more than $6.5 billion. 

Europe's biggest carmaker has admitted cheating in diesel emissions tests in the US and Germany's transport minister says it also manipulated them in Europe, where Volkswagen sells about 40% of its vehicles. 

The company is under huge pressure to address the worst business crisis in its 78-year history, which has wiped more than a third off its market value, sent shock waves through the global car market and could harm Germany's economy. 

"We are facing a long trudge and a lot of hard work," Mueller told a closed-door gathering of about 1,000 top managers at Volkswagen's Wolfsburg headquarters last night.  

"We will only be able to make progress in steps and there will be setbacks," he said, according to a text seen by Reuters. 

Mueller was appointed CEO on Friday to replace Martin Winterkorn. German prosecutors said this week they were investigating Winterkorn over allegations of fraud. 

The crisis is an embarrassment for Germany, which has for years held up Volkswagen as a model of its engineering prowess and has lobbied against some tighter regulations on car makers.

The German car industry employs more than 750,000 people and is a major source of export income.

Germany's KBA watchdog had set Volkswagen an October 7 deadline for it to present a plan to bring diesel emissions into line with the law. 

Volkswagen said previously about 11 million vehicles were fitted with software capable of cheating emissions tests.

This includes 5 million at its VW brand, 2.1 million at luxury brand Audi, 1.2 million at Czech division Skoda and 1.8 million ligh tcommercial vehicles. 

Refitting 11 million cars would be among the biggest recalls in history by a single car maker, similar in scale to Toyota's recall of more than 10 million vehicles between 2009 and 2010 over acceleration problems, though dwarfed by the number recalled by multiple carmakers due to faulty Takata airbags.

Volkswagen sold 10.1 million vehicles in the whole of 2014. 

The company said last week it would set aside €6.5 billion in its third-quarter accounts to help coverthe cost of the crisis. 

But analysts think that may not be enough, as it faces potential fines from regulators and prosecutors, as well as lawsuits from cheated customers. 

Sweden's chief prosecutor told Reuters today he was considering whether to start a preliminary investigation into Volkswagen. 

Mueller also said Volkswagen's core VW division, struggling with high-fixed costs and low profit margins, would be given more autonomy, akin to the independence enjoyed by premium flagship brands Audi and Porsche. 
              
Analysts have long urged the company to tackle the underperformance of its core mass-market brand, and in particular to dilute control from the centre which has been blamed for product delays and problems adapting to local markets. 

The emissions scandal has sent ripples through the global car market, with manufacturers fearing more costly regulations and a drop in diesel car sales. 

The European Commission is working on outline plans to reform the European system for approving new models of cars by the end of the year.

Investors to steer clear of VW over next 6 months - survey

A survey of 62 institutional investors by Evercore ISI shows that two out of three believe it will not be possible to invest in Volkswagen over the next six months if the financial risks linked to its emissions scandal remain unclear. 

"66% of investors responded that it is not possible to invest in VW over the next six months if costs, fines, legal and criminal proceedings are outstanding or inadequately quantified," Evercore analyst Arndt Ellinghorst wrote in a research note. 

The survey also showed that 76% of investors believe that VW should spin off its trucks business, while 62% said the company had too many brands,suggesting the group needs streamlining.