Klaus Esser was paid millions after the deal went through

Deutsche Bank chief executive Josef Ackermann and the head of the IG Metall union, Klaus Zwickel, were members of a committee that approved extra payments to former Mannesmann chief Klaus Esser and other executives when the company changed hands.

Charges against the three men and three other former Mannesmann officials were filed last week.

But the prosecutor did not confirm the details until Tuesday, after the charges had been served.

They follow a two-year investigation into whether members of Mannesmann's supervisory board breached shareholders' trust by approving payoffs of more than 100m euros (�68m; $108m) to smooth the takeover by Vodafone.

Prison sentence

Mr Esser had been bitterly opposed to Vodafone's hostile bid.

But he gave up his objections, and received a payment of about 30m euros once the deal went through.

Prosecutor Hans-Reinhard Henke alleged that Mr Esser had conspired with the supervisory board chairman Joachim Funk to authorise special payments for himself and other executives "in return for their support for a 'friendly' takeover of Mannesmann".

"The payments served purely for the enrichment of the beneficiaries in connection with Mannesmann's takeover, not the company's good," Mr Henke said.

Mr Esser has repeatedly denied any wrongdoing, arguing that the majority of Mannesmann shareholders were in favour of the takeover by the time he gave up his fight.

The charge of breach of trust carries a maximum sentence of 10 years in prison.