Cello has acquired just over 76% of cchm:ping for an initial consideration of approximately £950,000, of which £760,000 is payable in cash and the remainder by the issue of shares.
The remaining 24% is subject to put-and-call options exercisable in the period from 2008 to 2011, with the option prices being determined by the financial performance of cchm:ping during the period to December 31 2012.
The total maximum consideration for the acquisition of 100% of the Hill Murray Group, the holding company of cchm:ping, is approximately £5.3m in cash, loan notes and shares.
The client list for chm:ping includes Aegon, Bristol & West Mortgages, Legal & General, Nationwide, Lloyds TSB and Scottish Life.
Kevin Steeds, Cello chairman, said: "Cchm:ping is a highly regarded specialist financial services marketing agency with an excellent client base. As part of our Response division, based in London, it will complement our existing business and give us considerably more depth in the financial services sector vertical."
Cello acquired MRUK Research last month for £6m and invested in online market research firm Nqual in April.