
The agencies won the business after a pitch against Elvis, and will now work together to help raise the profile of the newly formed organisation and highlight the benefits that the merger will bring.
Work will incorporate both above-the-line and below-the-line campaigns, and will also include the development of ongoing supporter acquisition and retention activity.
The merger between Age Concern and Help the Aged means that the new charity now has a combined annual gross income of more than £150 million, making it one of the largest charities in the UK.
The organisation currently has more than 500 shops, and gives information and advice to more than five million old people across the country.
Nicola Mendelsohn, the chairman of Karmarama, said: "The merged organisation has a truly exciting mission, which will build on the rich heritage of the two previous organisations. As such, we are absolutely thrilled to be working with such a fantastic and high-profile client with such ambition and ideas."