Ad group WPP says still working to resolve Petya attack

WPP had joined other companies such as shipping giant A.P. Moller-Maersk in reporting disruption to its operations due to a cyber attack.

"We are working with our IT partners and law enforcement agencies to take all appropriate precautionary measures, restore services where they have been disrupted, and keep the impact on clients, partners and our people to a minimum," the company said in a statement on Wednesday.

"Our operations have not been uniformly affected, and issues are being addressed on a company-by-company basis. Many of our businesses are experiencing no or minimal disruption."

(Reporting by Kate Holton; Editing by Susan Fenton)