Four former Volkswagen managers and engineers, were due to go on trial in the German city of Braunschweig on Thursday.
They were being tried for their part in the VW diesel emissions scandal.
Among other things, the defendants were accused of commercial and gang fraud by using manipulated software on millions of cars.
The vehicles emitted many times, the permitted values for harmful nitrogen oxides on the road.
Shortly before the start of the trial, the criminal division of the Regional Court of Braunschweig, also known as Brunswick in English, ruled that proceedings against former CEO, Martin Winterkorn would be the subject of a separate hearing and decision.
Winterkorn, 74, had been suffering from health problems, following an operation.
The public prosecutor’s office had filed an appeal against the separation of the proceedings.
Regardless of the outcome of that appeal, a lengthy trial was expected. Currently, 133 trial days were scheduled up to the summer of 2023.