Construction will start next summer on a 95-hectare site, once home to Blyth Power Station in Northumberland.
Sources estimate the 2.7m sq ft factory project, which has been designed by Italian architect Pininfarina, could be worth approaching £300m.
Britishvolt will spend £2.6bn on the vast lithium-ion battery plant that will supply car batteries to the automotive industry when the first phase is up and running by the end of 2023.
Construction of a further two phases will continue until the end of 2027.
Previously, the firm was looking at a site in South Wales and had named N G Bailey as a delivery partner.
But earlier this month it plumped for the site in the North East of England.
Britishvolt CEO, Orral Nadjari, said: “We’re delighted to have engaged ISG as the construction partner for our Blyth gigaplant. Its long expertise of delivering global projects will be crucial to meeting our exacting standards and tight timeframe.
“Especially key is that ISG’s frontline team delivered Jaguar Land Rover’s production facility in Nitra, Slovakia, giving Britishvolt hugely relevant and recent experience in delivering large-scale projects such as ours.”
ISG chief executive, Paul Cossell, said: “The construction phase alone will directly support thousands of jobs in the North East and create a wealth of training and upskilling opportunities for local communities. The legacy of this major investment will benefit the region for generations to come.”
The plant will exclusively use renewable energy, including the potential to use hydro-electric power generated in Norway and transmitted 447 miles under the North Sea via the world’s longest inter-connector from the North Sea Link project.