"SMA is in the process to qualify additional suppliers for critical components such as semiconductors," Chief Executive Pierre-Pascal Urbon told analysts. "Due to our size and R&D competence we're in a very good position to bring on new suppliers in a short period of time."

SMA did not say which companies it was talking to and declined to comment on who its current suppliers are. SMA Solar is the last big German solar equipment maker after most others were wiped out by Chinese rivals.

Memory chip makers are enjoying a so-called super-cycle where increasing demand for more sophisticated devices, such as cloud-computing data centre servers, requires higher numbers of more expensive chips, triggering supply shortages.

Chips are a key component for SMA Solar's inverters, which are important parts of solar power stations that convert direct current generated from panels into alternating current and feed it into the power grid.

As a result of the bottleneck, SMA now sees sales of more than 900 million euros (£798 million), down from a previous forecast for sales of 900 million to 950 million euros and in line with the 907 million Thomson Reuters I/B/E/S estimate.

SHADOW OVER SHARES

Urbon said supply issues would also impact sales in 2018, which analysts expect to be flat at 902 million euros. SMA Solar will provide its 2018 outlook at a capital markets day scheduled for Jan. 26.

Shares in SMA fell as much as 16.6 percent to their lowest level in five weeks, with traders pointing to the lowered sales outlook, which the group had raised only in August.

"The fact that they're apparently not reaching the targets they've set out is quite a disappointment," one trader said.

SMA's nine-month earnings before interest, tax, depreciation and amortisation (EBITDA) halved to 55.3 million euros, it said. For the full year, it still sees EBITDA of between 85 million and 100 million euros.

Nine-month sales fell by 16 percent to 593 million euros, with weak business in large solar power parks in North America which was not offset by a rise in sales in Asia and Europe.

(Additional reporting by Anika Ross; Editing by Maria Sheahan and Alexander Smith)

By Christoph Steitz and Anneli Palmen