The chief executive of Deutsche Bank, Josef Ackermann, along with former Mannesmann AG CEO Klaus Esser, plus four other board members, have been on trial facing fraud-related charges. The other accused men were Klaus Zwickel (former head of IG Metall, Germany’s largest union), Dietmar Droste (former Mannesmann personnel chief), Joachim Funk (Mannesmann’s former chairman), and Jurgen Ladberg (former works council chief).

Ackermann, Funk, Zwickel and Ladberg were charged with breach of trust, while Esser and Droste had faced charges of abetting a breach of trust.

The charges stem back to the 154bn euro ($188bn) takeover of Mannesmann in 2001 by Vodafone Group Plc. German prosecutors allege that the 57m euros ($69m) worth of executive bonuses tied to the record bid for the German company were excessive and designed to overcome opposition to the takeover.

But at the end of a six month long trial, the presiding judge Brigitte Koppenhoefer found no compelling evidence of criminal activity by the defendants. She did however say that the awards, though legal under criminal law, weren’t in the company’s interest.

We don’t take any moral or ethical decisions, she told the court. We don’t judge Germany’s corporate culture. We are only a commercial crime court.”

The high-profile show trial started back in January, and had been running two days a week. It had been widely expected that the defendants would be acquitted, as the prosecution case looked shaky at best, and was dealt a body blow in late March when Koppenhoefer concluded that there was no proof of any criminal activity so far, and that criminal charges were unwarranted.

The long takeover battle for Mannesmann was an emotional issue in Germany, where there was general hostility to one of the cornerstones of the country’s economy being acquired by an overseas mobile phone operator.

The prosecution has already signaled it is considering appealing the verdict, and said it would decide in the next seven days whether to take the case to Germany’s highest court.