Its factories in China -- where it generates a tenth of sales -- are running at 95% of their pre-outbreak levels, Kaeser told reporters, while all but two of Siemens' factories globally were open.

"We observe the supply chain very closely - both the supply of our products and components to customers and the supplies to us. Both are running well, but that can change any day," Kaeser said.

Siemens had no final forecast how the outbreak would hit its business, but it would not be unaffected in the short term, Kaeser said.

"We are a strong business with good liquidity," said Kaeser, noting that service work for example on power stations or buildings was particularly volatile at present.

(Reporting by John Revill; Editing by Michael Shields)