FRANKFURT — Volkswagen was supposed to turn the corner this year from the shadow of a costly diesel emissions scandal, with a new emphasis on electric vehicles, a new logo and a new commitment to ethical behavior.

But on Tuesday, German prosecutors charged the automaker’s two highest-ranking executives with stock market manipulation for failing to inform shareholders of an investigation in the United States that led to its conviction for emissions cheating.

The allegations against Hans Dieter Pötsch, the chairman of Volkswagen’s supervisory board, and Herbert Diess, the chief executive, mean that the world’s largest automaker will be led by criminal defendants as it tries to refashion itself as a climate-friendly manufacturer of affordable electric cars. The prosecutors, in Braunschweig, also charged Martin Winterkorn, a former Volkswagen chief executive.

The day brought bad news for another German automaker, too, again tied to an emissions scandal. Daimler, the maker of Mercedes-Benz cars, agreed to pay a fine of 870 million euros, or $957 million, in Germany for selling diesel cars that polluted more than allowed. The company has disclosed that it is also under investigation in the United States.