The decorating giant is planning a consumer media blitz in a bid to raise awareness of the brand.
Bristol-based Corixa won the work after a four-way competitive pitch, which is understood to have included Campaign Marketing.
The agency's brief centres around consumer press relations and working with the retail trade, with initial project work surrounding the imminent launch of a range of radiator enamel.
Corixa will report to Hammerite and Cuprinol marketing manager Peter Hunt and brand manager Phil Palfrey.
Palfrey said the decision to repitch the brief followed the merger of marketing and sales teams for the Hammerite and Cuprinol brands. Corixa has handled PR for Cuprinol for more than eight years.
'We are trying to get a co-ordinated message across both brands,' said Palfrey. 'Hammerite hasn't moved forward on where it was in the UK for a number of years.'
Palfrey said PR has focused on Hammerite's expansion into Europe during the past few years, rather than its presence in the UK.
'The team is now looking at this with fresh eyes and the potential for growth into other sectors, such as the garden market,' he added.