"Based on our current information, we have so far not been infected by the malware," Markus Krebber said after presenting first-quarter results.

Spanish energy firms Iberdrola and Gas Natural on Friday asked staff to turn off computers or cut off internet access in case they had been compromised, following the spread of the virus WannaCry.

Krebber also said that RWE's trading unit expected more volume growth in the global market for liquefied natural gas (LNG), especially with more supply coming out of the United States, Australia and Africa. "We want to participate in trading opportunities," he said.

(Reporting by Christoph Steitz and Vera Eckert; Editing by Maria Sheahan)