BERLIN • As Volkswagen (VW) seeks to replace discredited chief executive officer (CEO) Martin Winterkorn, the leading candidates range from a decades-long veteran of VW to a pair of newcomers who have been with the company less than a year.

Mr Winterkorn resigned on Wednesday after revelations that the firm cheated on diesel emission tests and may face criminal charges in the affair. The carmaker's supervisory board said it will discuss his replacement at its meeting today.

Possible successors include Porsche unit chief Matthias Mueller, who is backed by members of the family that controls a majority stake in Volkswagen, and former BMW executive Herbert Diess, who took over the newly created post of VW brand chief this year, a person familiar with the matter said.

The new CEO will take charge as VW seeks to regain consumers' trust and rebuild a brand tarnished by scandal. Its admission that millions of its "clean diesel" cars have software intended to defeat emissions tests has wiped nearly €20 billion (S$31.8 billion) off its market capitalisation since last Friday.

Mr Winterkorn's departure "was necessary for the company, for the workers, for the region, for Germany's car industry, but it's only a first step," said Christian Democrat lawmaker Guenter Lach, who worked at VW for four decades. "Volkswagen has been shaken to the core. The company now stands at the beginning of a long, painful series of corrective actions."

Mr Mueller, 62, has led Porsche since 2010 and could be an interim CEO to stabilise VW until a longer-term candidate can be groomed, said analyst Arndt Ellinghorst of Evercore ISI in London. Mr Mueller started at Audi as a toolmaking apprentice in the early 1970s, and his focus in recent years has been away from the VW and Audi brands named in the diesel affair. Mr Ellinghorst said that if Mr Mueller were chosen, he might quickly be succeeded by Mr Diess, 56, or Volkswagen trucks chief Andreas Renschler, 57. "They need fresh people, a new system," Mr Ellinghorst said.

Mr Diess spent 18 years at BMW, including stints running purchasing and model development. He left the firm at the end of last year. Mr Renschler worked at Daimler for 25 years and started at VW in February.

Volkswagen set aside €6.5 billion on Tuesday in an initial tally of the potential cost of its deception of regulators and customers about emissions of diesel engines installed in 11 million cars worldwide.

BLOOMBERG