(Bloomberg) -- Infineon Technologies AG shares plunged after its fourth-quarter margin outlook missed estimates and the German chipmaker said that costs, including new investments and expenses for equipment sitting idle, had increased. 

The segment result margin, an adjusted measure of profitability that excludes extraordinary items, is expected to be 25% in the fourth quarter, Infineon said in a statement on Thursday. That compared to analysts’ 26% estimate, according to the average forecast in a Bloomberg survey. 

Infineon is spending billions of euros to increase its manufacturing capacity. The company said in a separate statement on Thursday that it would invest as much as €5 billion ($5.5 billion) in the next five years to expand its plant in Malaysia. That’s in addition to another buildout in Dresden. 

Read More: Infineon to Invest Up to €5 Billion in Malaysia Site Expansion

Meanwhile, costs for factories that aren’t being fully utilized, so-called idle costs, also contributed to declining margins, Chief Financial Officer Sven Schneider said in a call to discuss the results. He attributed that to weakness in the consumer electronics market, “so the factories are a little emptier at this point.” 

Third quarter margins fell from the previous period, and the outlook for potential declines in profitability is worrying investors, Jefferies analyst Janardan Menon said in a note. Falling margins in the company’s key automotive segment are of particular concern, he said. called the semiconductor market a “mixed picture.” 

Read More: European Stocks Slide as Infineon’s Weak Outlook Weighs on Tech

Shares fell 10% at 1:49 p.m. in Frankfurt trading after earlier falling as much as 12%, the biggest intraday decline since March 2020. The stock has gained about 21% this year. 

(Updates with CFO comments from results call in fourth paragraph)

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