First Solar, the largest U.S. solar equipment maker, said it would slash about 1,600 jobs, or 27% of its global workforce, to cut costs as it transitions to production of Series 6 modules.

The company also forecast on Wednesday 2017 net sales of $2.5 billion-$2.6 billion, well below analysts’ average estimate of $2.98 billion, according to Thomson Reuters tri .

First Solar fslr said the restructuring is expected to result in pretax charges of between $500 million-$700 million, anticipated primarily in 2016.

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The company warned earlier this month of significant challenges next year due to a 30% slide in prices, driven by lower demand in China and the resulting oversupply of panels globally.