Volkswagen Stock Plummets As CEO Apologizes For Emissions Cheat

Updated 7:30 p.m. ET

"I personally am deeply sorry that we have broken the trust of our customers and the public," says Volkswagen CEO Martin Winterkorn, days after the EPA said the German carmaker had purposefully rigged its diesel cars to pass emissions tests.

The CEO's sentiments did not stop investors from punishing VW's stock Monday in Europe, when they hacked away nearly a quarter of the company's market value.

"The shares plunged as much as 23 percent to 125.40 euros in Frankfurt, extending the stock's slump for the year to 31 percent," Bloomberg reports. "The drop wiped out about 15.4 billion euros ($17.4 billion) in value."

The steep drop came Monday, the first day of trading since the Environmental Protection Agency said it had found Volkswagen had for years used trickery to get around U.S. emissions laws.

Volkswagen is facing as much as $18 billion in fines, according to the Associated Press. It also reports that a Volkswagen official confirmed that the Justice Department had contacted the company regarding the case. AP notes that this case could test the Justice Department's resolve to hold individuals accountable for corporate crimes.

Michigan Radio's Tracy Samilton reports for our Newscast unit:

"The German automaker will have to recall about 482,000 Audi and Volkswagen cars with 4-cylinder turbo diesel engines. The issue affects 2009 through 2015 model years.

"The cars have devices that turn emissions controls on during tests and off during normal driving.

"The deception is a serious violation of the Clean Air Act, for which CEO Martin Winterkorn says he is personally deeply sorry, and he promises the company will do whatever is necessary to reverse the damage this has caused. The company faces potentially billions in fines and other costs."

On Friday, the EPA and the California Air Resources Board said that a "defeat device" had allowed diesel Jettas, Beetles and other cars to "emit up to 40 times more pollution" than allowed under U.S. standards.

Saying that Volkswagen has ordered an external investigation of the software exploit that skirted U.S. emissions tests, Winterkorn stated, "We do not and will not tolerate violations of any kind of our internal rules or of the law."

He added, "The trust of our customers and the public is and continues to be our most important asset."

In Germany, the fallout ranges from calls for the German government to investigate the matter to new tensions in Volkswagen's leadership ranks, which had been emerging from a power struggle between Winterkorn and former chairman Ferdinand Piech, who resigned nearly five months ago.

VW now also faces the possibility that other governments, in Europe and beyond, will take a closer look at the technology in its cars that run on diesel, a fuel that's far more popular outside the U.S. than in it is here in the domestic market.