Josef Ackermann will step down from Siemens AG’s supervisory board, two weeks after he resigned as chairman of Zurich Insurance Group AG following his naming in the suicide note of finance chief Pierre Wauthier.

The decision of the former Deutsche Bank AG Chief Executive Officer to quit as Siemens deputy chairman is not connected to Zurich Insurance and was made “quite independently and for completely different reasons,” Ackermann told reporters in Berlin at the presention of his biography. The move was prompted by disagreements over the ousting of former Siemens CEO Peter Loescher, according to a person familiar with the situation.

Siemens, Europe’s largest engineering company, in July ousted Loescher, following a fifth profit forecast cut in his six years and replaced him with finance chief Joe Kaeser. Ackermann opposed the move, which was driven by Chairman Gerhard Cromme, people familiar with the matter said at the time.

“As I’ve have made clear, I react emotionally when principles of fairness are violated,” Ackermann said today.

While other German industrial champions have prospered during the European credit crisis thanks to their strength in exports outside Europe, Siemens has floundered.

Since Loescher, who was recruited by Cromme, took over in July 2007, the shares have declined 15 percent through yesterday. Germany’s DAX index gained 6 percent in that period. Today, the stock dropped 1 percent as of 1:47 p.m. in Frankfurt trading, valuing Siemens at 77 billion euros ($102 billion).

‘Internal Conflict’

“Ackermann was a very competent member of the board and from that perspective it’s a shame that he’s leaving,” said Commerzbank AG analyst Ingo-Martin Schachel. “There have been many reports about conflicts between him and other members of Siemens’s supervisory board. Having a lower level of internal conflict potential at Siemens would be a good thing.”

Ackermann didn’t inform Siemens’s board or senior management before quitting his post at Zurich Insurance, a person with knowledge of the matter said last month.

Wauthier, found dead on Aug. 26 at his home near Zug, Switzerland, mentioned Ackermann in a suicide note. The 65-year- old Swiss native quit as Zurich Insurance chairman three days later and called the allegations “unfounded.”

The CFO’s suicide sparked fresh doubts about Zurich Insurance’s financial health after it missed analysts’ profit estimates in three of the past four quarters and announced a surprise write-off in October. That prompted CEO Martin Senn to tell analysts on a conference call on Aug. 30 that there’s no link between Wauthier’s death and the company’s business.

‘No Link’

Ackermann said today that while the need for action at Zurich Insurance was “considerable,” his discussions with Wauthier were marked by respect.

Zurich Insurance has said it’s looking into whether undue pressure was placed on the CFO. The Swiss company yesterday confirmed that Tom de Swaan, who had become chairman on an interim basis after Ackermann’s departure, would assume the role permanently.

While carrying out tasks at the Swiss insurer had become impossible, Ackermann said today he will remain in other posts. He is a board member of oil producer Royal Dutch Shell Plc and Investor AB, the publicly traded company of Sweden’s billionaire Wallenberg family.

As CEO of Deutsche Bank, Ackermann helped transform a German-focused institution into Europe’s largest investment bank, steering the company through the global financial turmoil of 2008 and ensuing euro-region fiscal crisis. In May 2012, he ended his 10-year career at the helm of the Frankfurt-based lender.

With assistance from Nicholas Comfort in Frankfurt and Patrick Winters in Zurich. Editors: Simon Thiel, Andrew Noel