By Christoph Steitz and Christina Amann
FRANKFURT/BERLIN (Reuters) -A record sell-off in Siemens Energy shares has laid bare a major loss of confidence by investors in the group's ability to fix its struggling wind turbine division, leaving them fearful of what else to expect down the road.
Siemens Energy's stock plunged by a third on Friday, knocking nearly 7 billion euros ($7.6 billion) off the group's market value, after it warned of deeper quality problems at Siemens Gamesa - just weeks after the group managed to acquire the remaining stake in the wind turbine unit.
The full takeover, first outlined last year, was the result of Siemens Energy's inability to address Siemens Gamesa's long-standing operational problems as the owner of a majority, but not 100%, stake in the separately listed entity - a structure inherited following the spin-off from Siemens.
The takeover of the remaining third it did not already own in Siemens Gamesa cost the German group 4.05 billion euros and was sold by Siemens Energy as a way to get a better handle on the problems.
"If there is reason to believe there are more skeletons in the closet than initially thought, I would wait before any takeover," Felix Schroeder of Siemens Energy shareholder Union Investment said.
"They had time ... But apparently they were not ready. That is disappointing and now costs hard-earned credibility," Schroeder said. "You have to ask the question why they didn't realise this earlier and why they didn't wait with the takeover."
Siemens Energy CEO Christian Bruch said on Friday that the takeover of Siemens Gamesa had not been a mistake and that the price had seemed right at the time when the offer was made.
The latest problems come more than a year after Jochen Eickholt - Siemens Gamesa's third CEO since the company was created in 2017 via the merger of Siemens AG (ETR:SIEGn)'s wind activities and Spain's Gamesa - was brought on board to stop the bleeding.
'SO MANY QUESTIONS'
Top-20 investor Deka Investment said "significantly greater efforts" were now needed by Siemens Energy, chaired by Siemens veteran Joe Kaeser, to restore trust.
That could be a tough task given that problems at Siemens Gamesa, which include faulty turbine components and possible design flaws, are long-standing and have caused multiple profit warnings over the past year and a half.
Siemens Energy said late on Thursday the new quality issues could impact up to 30% of Siemens Gamesa's installed onshore fleet, but it was management's inability to put a firm number on the potential future financial damage that concerned investors.
"I have so many questions that it's difficult to pick just one," Gael de-Bray, European head of capital goods research at Deutsche Bank (ETR:DBKGn), said during an investor call hastily arranged for early Friday.
Berenberg analysts pointed out that Siemens Energy had given a fairly upbeat view on Siemens Gamesa along with second-quarter results only a month ago, and that Thursday's announcement did not fit with the recent communication.
"To us, it is the stark change in message since Q2 that reflects so poorly," they wrote.
Siemens Energy CEO Bruch also cited the need to fix Siemens Gamesa's corporate culture, hinting at the fact that the company's merger never fully worked and that major management mistakes were made.
The merger took place under the leadership of Joe Kaeser, then CEO of Siemens, who has since acknowledged that the cultural divide between the two companies had been underestimated.
When asked earlier this month on whether Siemens Energy was doing well enough to master the challenges of the energy transition, Kaeser said the management team led by Bruch was strong.
"If they can't do it, no one can."
($1 = 0.9189 euros)