The agency has been handed a new integrated public affairs and PR brief following a pitch initiated last year.
Hanover's task will be to demonstrate the importance of steel to the UK economy and growth agenda.
A particular focus will be on showing how it is helping the country become a world leader in high value-added manufacturing.
The public affairs element will be led by Rhoda Macdonald and Lucy Gilchrist, Hanover’s head of energy and environment – who will also project manage all activity.
The PR side of the account will be led by Gavin Megaw and Gonzalo Vina, who recently joined Hanover from Bloomberg. Altogether, the brief is believed to be worth a mid six figure sum.
Tata Steel’s director of corporate comms and public affairs, Sytske Seyffert, pointed to London’s developing skyline and the UK's reviving car industry as examples of the need for steel.
She added that steel was the "foundation on which a more balanced economy is being built".
Last November the Indian company announced UK restructuring plans leading to the loss of 600 jobs at its plants in Wales, where it employs 7,500 people.
It employs more than 20,000 staff across the UK as a whole.