Shares of Barrow-in-Furness marine engineering services company James Fisher and Sons plc fell about 6% on Tuesday after it said it has been subject to a “cyber security incident” which involved unauthorised access to its computer systems.

James Fisher provides services to the oil and gas, marine, defence and nuclear industries.

In a stock exchange statement, James Fisher said: “JFS took immediate steps to respond to and manage the incident, appointing external specialists, including forensic cyber security experts to investigate the circumstances and scope of the incident.

“These investigations are ongoing.  

“As a precautionary measure JFS took all affected systems offline.

“This has restricted access to communication and financial systems.

“Following containment of the incident, we are working with our cyber security experts on a safe recovery of systems, applications and data from our disaster recovery back-up.

“Work is ongoing to complete the recovery as quickly as possible and to minimise any impact on our businesses.

“As a responsible global business we have notified regulators and law enforcement agencies in the UK and, where required, are in the process of notifying in other jurisdictions.

“A further update will be made in due course.”

Fisher reported 2018 revenue up 13% to £561.5 million and underlying profit before tax up 15% to £56.1 million.

Fisher has a stock market value of around £1 billion.