09/21/2015 10:42 EDT | Updated 09/21/2016 05:12 EDT

Volkswagen Shares Plunge As Much As 23% Over Emissions Scandal

Shares of Volkswagen AG saw their steepest drop in at least seven years after the U.S. Environmental Protection Agency said the automaker had intentionally rigged its cars to pass emissions tests.

The CEO of Volkswagen, Martin Winterkorn, apologized over the weekend, following the EPA's order that 500,000 Volkswagen and Audi vehicles in the U.S. be recalled due to software that kicks in emissions regulation systems in cars -- but only when the car is being tested for emissions.

"I personally am deeply sorry that we have broken the trust of our customers and the public," Winterkorn said in a statement.

But investors weren't impressed with the apology, sending Volkswagen shares down as much as 23 per cent Monday. That would have wiped C$23 billion off the market value of Volkswagen.

The EPA recall affects Audi A3, VW Jetta, Beetle, Golf and Passat models build over the past seven years.