(new: share price, chart technology and further analysts)

FRANKFURT (dpa-AFX) - Black Friday for the shareholders of Siemens Energy: After withdrawn forecasts, the shares of the power engineering group crashed before the weekend. Already at the start, they lost more than a third and, at just over 15 euros, cost as little as last in November. Trading was interrupted several times at the start due to excessive fluctuations.

Shortly after midday, the share price was still down 33.3 percent at 15.60 euros. Shares in major shareholder Siemens also came under pressure in the wake of Energy, falling 2.8 percent. The leading Dax index continued its weak week by losing around 0.7 percent.

Wind turbine manufacturer Siemens Gamesa remains the Dax group's problem child. There have been significantly increased failure rates in wind turbine components, Siemens Energy said. A technical review suggests that fixing the problems with certain onshore platforms will cost significantly more than previously thought, it added. Siemens Energy currently expects additional costs to exceed one billion euros. In January, the cost had been put at 472 million euros.

This is very bad news, said one trader. If there was no indication of where the costs were going, how was the market supposed to assess it, the trader worried. He spoke of "total uncertainty."

The new problems at subsidiary Gamesa put a dark cloud in front of the group's revaluation story, Goldman Sachs analyst Ajay Patel wrote in an initial reaction. He evaluates the message "clearly negative". Not calculable are currently the financial consequences of the quality problems at Gamesa, wrote Nicholas Green of the U.S. analyst firm Bernstein Research.

If it remains at the end of trading for Siemens Energy with the price loss in the current order of magnitude, Siemens Energy would be in the extended circle of the largest daily losers, which there was ever in the DAX. Measured in terms of the stock's value, the loss is currently more than six billion euros.

Until the previous day, the shares had been among the biggest winners in the Dax since the beginning of the year. They started their rally in mid-October and posted a peak gain of 140 percent in the period to the end of May. Now, however, they also fell below the support area of the 61.8 percent Fibonacci retracement. This means that they have lost more than 61.8 percent of their gain since October - in charting terms, this is considered a massive warning signal for the entire trend. Since the beginning of the year, the papers are down eleven percent in one fell swoop, putting them at the back of the Dax field.

The wind power subsidiary Gamesa is a well-known problem for Siemens Energy, explained the capital market expert Jürgen Molnar of the broker RoboMarkets. However, after the complete takeover at the beginning of the year, Gamesa has so far proved to be a black hole in the balance sheet. "The future of Siemens Energy depends more and more on whether it gets a grip on the problem child." The bitter part of the current sell-off in Energy shares is that it brings the strong recovery since last October to an abrupt end, the expert said.

Potential buyers who could take advantage of Siemens Energy's low share price to enter the market have not yet appeared on the scene on Friday. Bernstein analyst Green also advises investors against it. In the worst case, namely if more than 30 percent of Gamesa's installed turbines are faulty, there is a threat of an even more significant slide in the share price. If Gamesa were valued at zero, the fair value of Siemens Energy would be eleven euros, Green calculated.

Market observer Alexander Paulus of Stock3 sees the next important supports in the price chart at 14.37 euros and 13.36 euros. Until then, the papers would still have some room. In general, however, he advises after such price collapses to let the shares "settle out first" and to wait for a first attempt to form a bottom. Chart supports rarely have an effect in the midst of a selling panic./ajx/tih/ag/jha/