* CEO says can only speculate about any further provisions
* Supervisory board member Weil says October sales stable
* CEO says too early to anticipate results of investigation
* Head of group quality control suspended - sources (Adds suspension of head of group quality control)
By Andreas Cremer
WOLFSBURG, Germany, Oct 21 (Reuters) - Volkswagen may have to set aside more than the 6.5 billion euros ($7.4 billion) it has so far allocated to cover the costs of an emissions scandal if car sales suffer, its chief executive said on Wednesday.
“The 6.5 billion (euros) applies to the recall,” Matthias Mueller told reporters after a tour of VW’s headquarters in the German town of Wolfsburg.
“I can only speculate about any further provisions. Should there be a change in sales volumes, we would react rapidly.”
Lower Saxony Premier Stefan Weil, a VW supervisory board member, said sales had been stable in October so far.
Volkswagen also confirmed it had stopped the sale within the European Union of new cars containing the software that can cheat diesel emissions tests.
VW admitted on Sept. 18 it used illegal software to manipulate emissions tests on diesel vehicles in the United States, sparking the biggest business crisis in its history.
The admission has wiped about a quarter off its stock market value, forced out its long-time chief executive and sparked investigations and lawsuits across the world.
Volkswagen has suspended Frank Tuch, head of group quality control, two people familiar with the matter told Reuters.
Tuch is the fifth suspended worker whose name has become public. Volkswagen declined to comment and Tuch did not reply to repeated attempts by Reuters to contact him.
Asked whether a small group of employees could have alone been responsible for the deception, Mueller said: “We are still deep in the middle of the clarification, including the question of the possible culprits and causes.”
Mueller, who replaced former chief executive Martin Winterkorn a week after the scandal broke, said the investigations were “relatively extensive and complicated” and went back to 2005.
$1 = 0.8818 euros Reporting by Andreas Cremer; Writing by Georgina Prodhan and Harro ten Wolde; Editing by Keith Weir and Pravin Char