It's likely to rank as one of the most closely-watched trials in German corporate history. Starting Wednesday, the head of Deutsche Bank, the former head of Germany's biggest trade union, and the former supervisory board of mobile phone company Mannesmann will be spending two days a week in a Düsseldorf court facing charges they unlawfully approved payments to top company executives.

The six men have been accused of violating shareholders trust. Prosecutors say they took advantage of British telecommunications company Vodafone's takeover of its German rival Mannesmann in 2000 to approve around €57 million ($71 million) in bonuses to the German firm's managers.

Making waves

Compared to the United States, where such payments are commonplace, the Mannesmann case has made waves in Germany, where pay differerentials between board members and average employees remain comparatively low. It's also the first time German business leaders have faced prosecution for supervisory board activities.

"This is the only country where people who are creating value go to court for doing so," Ackermann told reporters on Wednesday, according to the Reuters news agency.

As the head of Deutsche Bank, Swiss-born Josef Ackermann is arguably Germany's most powerful banker, and he's still on the job, despite the charges against him. Deutsche Bank has stood behind Ackermann throughout the saga. If convicted, it's unlikely that he or his co-defendants would serve jail time. But a guilty verdict would probably cost Ackermann his job.

Indecently high?

Klaus Esser, Mannesmann's former chief executive and the main beneficiary of the bonuses, has repeatedly stressed that there was nothing indecent about the nearly €30 million in bonuses and severance pay he received. "I believe that the level of the payments should be gauged according to the manager's success," he has said and points to the fact that during his time as CEO Mannesmann shares more than doubled.

But Klaus Zwickel, former head of IG Metall, Germany's most powerful labor union (as with all large corporations, unions represent the workers' interests on the supervisory board), has subsequently berated himself publicly, saying he should have voted against the payments that were "indecently high and incomprehensible for any worker." At the time, though, he effectively authorized the payments by abstaining from voting.

Prosecutors spent three years investigating the case and filed breach of trust charges against Ackermann, Zwickel, former supervisory board chairman Joachim Funk and worker's council representative Jürgen Ladberg. Esser and personnel director Dieter Droste are accused of aiding and abetting the four members of the supervisory board.

Initially, prosecutors in Düsseldorf considered charging the co-defendants with paying bribes to the managers to encourage them to drop objections to the €190 billion Vodafone takeover but decided on the "breach of trust" accusations instead.

The trial is expected to go on through June.