The research firm, which was founded in 1996 and recorded a turnover of £5.7m for the last year, provides product development, creative marketing communications and strategic media planning services to a range of clients, as well as a traditional market research and consultancy business.
Cello Group said it had acquired the agency for an initial cost of around £5.4m, with further performance related conditions raising that value to a maximum of £5.5m between now and the end of 2010.
The group said the buying of 2CV Limited, which recorded gross profits of £4m and pre-tax profits of £0.7m for the year ending May 31 2007, was being funded by £3.5m in cash and loan notes, and around 1.3m issued shares.
Kevin Steeds, chairman of Cello Group, said: "2CV has an excellent reputation within the marketing industry as a thought-leading and innovative consumer insight agency. The 2CV acquisition is consistent with our strategy of building a substantial international research and consulting group."