FRANKFURT, Germany — The fallout from Volkswagen’s emissions-cheating scandal intensified Wednesday, as investors dumped the company’s stock and a credit ratings agency downgraded its debt.
European regulators demanded VW speed up its investigation into the cheating, while the company halted sales of seven models in the U.S. that allegedly were part of the plot.
The latest developments followed Volkswagen’s admission Tuesday that it had understated the carbon-dioxide emissions for 800,000 cars, widening the scope of the scandal.
The company has been unable to halt the flow of bad news since mid-September, when the U.S. Environmental Protection Agency said Volkswagen had installed software on 482,000 cars with small diesel engines that enabled them to cheat on emissions tests for one pollutant, nitrogen oxide.
The software reduced emissions when the car was on a test stand. Volkswagen acknowledged that 11 million vehicles worldwide have the software.
On Monday, the EPA charged that Volkswagen also used cheating software in some cars with larger diesel engines, including Volkswagen’s elite Porsche brand.
Volkswagen denied the claim, but over the past two days it halted sales in the U.S. and Canada of the models involved: Volkswagen Touareg, Porsche Cayenne, and Audi A6, A7, A8, Q5 and Q7.
Late Tuesday, VW said it also had found “unexplained inconsistencies” in emissions from some of its vehicles of carbon dioxide, a gas that scientists say contributes to global warming. None of the cars were sold in the United States.
The company said the carbon dioxide problem could cost it 2 billion euros ($2.2 billion), on top of 6.7 billion euros ($7.3 billion) it had already set aside to cover the costs of recalls. Analysts say the total costs in fines and lost sales could be several times that.
Amid concerns over the escalating costs, the German carmaker’s ordinary shares slid 9.5 percent to close at 100.45 euros ($109).
