Tata has sold its Scunthorpe steel plant to turnaround specialist Greybull Capital, in a deal which will see its steelworks business renamed as British Steel.
The move will save around a third of the 15,000 British steel jobs which have been threatened by Tata's decision to sell its UK assets.
Greybull will also take on two mills in Teesside, an engineering workshop in Workington, a design consultancy in York and associated distribution facilities, as well as a mill in northern France.
The sale to Greybull - for a nominal pound or 1 euro - includes a £400 investment and financing package for the Scunthorpe business.
It's expected to go through within eight weeks, subject to the completion of financing agreements, as well as agreements with major suppliers.
Bimlendra Jha, executive chairman of the stand-alone Long Products Europe business, said: “Today marks a significant milestone in the sale of the Long Products Europe business."
"This sale is the best possible outcome for employees who have worked relentlessly to ensure the business’s survival, and helped to make it attractive to a potential buyer.”
Hans Fischer, chief executive of Tata Steel’s European operations, added: “Under these current challenging market conditions in Europe with the soaring levels of imports from China, we are happy that Tata Steel UK and Greybull Capital have entered the final stage of completion of the sale of shareholding in Longs Steel UK."
Marc Meyohas, a partner at Greybull, said: "We are delighted to have reached agreement for the acquisition of Long Products Europe, which we believe can become a strong business, with a highly skilled workforce and great potential."