Volkswagen's share price plunged mid-morning after revealing it will set aside €6.5bn (£4.2bn) to deal with the escalating emissions-cheating scandal as it admitted at least 11m vehicles could be affected.
The car giant said the write-down was needed to cover "the necessary service measures and other efforts to win back the trust of our customers".
"Due to the ongoing investigations the amounts estimated may be subject to revaluation, " VW added. "Earnings targets for the group for 2015 will be adjusted accordingly."
Volkswagen's share price was down 18 per cent at pixel time, having fallen 18 per cent yesterday.
"Volkswagen does not tolerate any kind of violation of laws whatsoever. It is and remains the top priority of the board of management to win back lost trust and to avert damage to our customers. The Group will inform the public on the further progress of the investigations constantly and transparently."
The statement this morning added Volkswagen was "working at full speed to clarify irregularities concerning a particular software used in diesel engines".
So far it has identified "discrepancies" relating to "some 11m vehicles worldwide" with type EA 189 engines. "A noticeable deviation between bench test results and actual road use was established solely for this type of engine," the car firm said. "Volkswagen is working intensely to eliminate these deviations through technical measures. The company is therefore in contact with the relevant authorities and the German Federal Motor Transport Authority"
But the problem could extend beyond these 11m vehicles, Volkswagen admitted.
"Further internal investigations conducted to date have established that the relevant engine management software is also installed in other Volkswagen Group vehicles with diesel engines," the group said. "For the majority of these engines the software does not have any effect."
The statement added: "New vehicles from the Volkswagen Group with EU 6 diesel engines currently available in the European Union comply with legal requirements and environmental standards. The software in question does not affect handling, consumption or emissions. This gives clarity to customers and dealers."