Nexus are offering a £1,000 cash reward for information leading to the arrest and conviction of the person or people responsible for the cable theft which brought disruption to the Tyne and Wear Metro system on Monday 28 May.
The theft happened near Hebburn and Jarrow Metro stations in the early hours of Bank Holiday Monday morning.
The incident resulted in part of the Metro system being closed for six hours, leading to disruption for passengers who had to travel on replacement buses.
Northumbria Police are carrying out enquiries in the area and are appealing for information.
Chris Carson, Metro Services Director, said: “The railway industry takes metal theft very seriously because of the impact it has on passengers. For this reason Nexus is offering a £1,000 reward for information leading to the arrest and conviction of those responsible for this attack.
"We are determined to do all we can to help the police in its investigation.”
Anyone with information is asked to contact Northumbria Police on 101.