In response to the story, the company used a statement overnight to say it is considering "potential further development in the management structure in the Volkswagen Group and potential personnel changes in the Board of Management".
Volkswagen shares, which closed 4.5 percent up on Tuesday after reports of Diess's likely appointment, gained 0.9 percent on Wednesday to 173.16 euros.
German carmaker Volkswagen is considering replacing its CEO Matthias Muller in a management reshuffle.
Mueller's contract with the German carmaker is set to run until 2020, but it confirmed on Tuesday that it was considering a change of leadership as it looked to complete a broader management overhaul.
VW has admitted to using software, known as a defeat device, in the 2009-2015 Audi A3 and the Volkswagen Beetle, Golf, Jetta and Passat TDI cars with 2.0-liter diesel engines to trick emissions tests. The statement said the board was considering changes that included the position of the CEO, and Mueller had signaled his "general willingness to contribute to the changes". Previous executives including Bernd Pischetsrieder and Wolfgang Bernhard struggled to push through such reforms. German newspaper Der Spiegel has reported that the changes could take place as soon as Friday.
VW (vlkay) said in a statement earlier on Tuesday that Chairman Hans Dieter Poetsch is now in discussions with top executives and supervisory board members about management board changes and that Mueller, 64, has "showed his general willingness to contribute to the changes".
The management revamp comes after the company posted record profit a year ago. According to the company, final decision is expected to be made by the end of the week.
The debate about Volkswagen's future structure comes a month after its largest shareholder, Porsche Automobil Holding, picked three new representatives of the Porsche and Piech families to help oversee Volkswagen.
Sources close to the board have told Reuters Mueller has become frustrated with the lack of support for his plans to reform the company.
Volkswagen and the works council declined to comment.