The other agencies involved were not disclosed, but one is believed to have been based in York, while the other was a large London agency.
Benenden, founded in 1905, has traditionally handled all DM work in-house. It has hired KLP Euro RSCG to handle an ambitious acquisition drive to help maximise potential growth of its 1m customer base.
Duncan Bradshaw, marketing and membership director at Benenden, said "As a mutual society we have a duty to our members to do our best to ensure every investment we make provides adequate returns -- whether that investment is financial or in marketing."
Bendendon, which is run by members, provides alternative and affordable healthcare to the NHS for its members, which include employees from the Post Office, the civil service, BT, the education sector, local authorities, and other approved public bodies.
KLP's first task will be a test campaign to selected teachers and head teachers throughout the summer term. If this is successful, the drive will be extended to target teachers nationally during the autumn term.
Names have been bought in from the NAHT and PAT and the work will include direct mail and inserts with the NAHT newsletter.
Hugh Treacy, managing director at KLP said: "The ambitious task Benenden Healthcare has set required KLP Euro RSCG to demonstrate both sensitivity to and understanding of a unique and complex consumer proposition. We are very excited by the creative being developed to communicate this proposition and look forward to developing the relationship with Benenden and its members."
If you have an opinion on this or any other issue raised on Brand Republic, join the debate in the .