It warned, however, that the business outlook might have to be adjusted should the crisis persist and impact the turbine sector in coming weeks and months.

"So far we don't have shortages of supply," CEO Jose Luis Blanco told Reuters after publishing final results for 2019, adding that the group had not yet been approached by clients to delay orders. "But that might still happen."

Blanco said that Nordex's production sites were currently running at about 90% capacity, simply because some employees were in quarantine while others could not be moved between sites due to current travel restrictions.

The group forecast consolidated sales of 4.2-4.8 billion euros ($4.5-$5.2 billion) and earnings before interest, tax, depreciation and amortisation (EBITDA) of 160-240 million euros this year.

This would represent a sales increase of 27-45% and a 29-94% rise in EBITDA, boosted by its 5.5 billion euro (5.1 billion pounds) order book, which was up 43% year-on-year.

Shares in the group, which counts Spain's Acciona as its top shareholder and competes with sector heavyweights Siemens Gamesa and Vestas, soared 18% to the top of Germany's technology index.

Analysts at consultancy Wood Mackenzie, however, took a more reserved view, expecting key markets, including China, the United States, Spain, France and Italy, to be hit by lockdown measures hurting worker mobility.

"Production in those countries is also starting to suffer with factory closures mounting this week due to coronavirus infections," said Dan Shreve, Wood Mackenzie's head of global wind energy research.

Blanco said the group, which also said it won a 400 megawatt supply and maintenance contract from Norway, continued to further develop its global supply chain.

(Editing by Michelle Martin, Kirsten Donovan)

By Christoph Steitz