Steeds, aged 50, died last night, leaving behind a wife and three young children.
He had been in intensive care since falling ill in September, at which time Cello announced that he would be temporarily stepping down from his role.
Steeds chaired the Cello Group, which owns various market research, data, direct marketing and creative agencies, including Insight, Leapfrog, Tangible Data, Tangible Response and Leith, since its incorporation in May 2004.
Mark Scott, group chief executive, said: "Cello really was Kevin's brainchild. The very name itself was Kevin's invention, and it took all his passion, grit and energy to get Cello off the ground.
"Kevin played a major role in building Cello and shaping the group's unique philosophy of being 'different' in the way the individual businesses work together collaboratively in partnership while retaining their independence."
Scott has been handling Steeds' responsibilities since September with the assistance, on a part-time basis, of Allan Rich, one of Cello's non-executive directors, who became acting chairman.
Cello Group said that there was "no immediate intention to replace Steeds".
Richard Gilmore, chairman of Cello Research & Consulting, said: "Kevin will be sadly missed, for those of us who knew and worked with him, we remember Kevin as a warm, friendly man who was genuinely interested in how we were all doing."
A memorial service for Steeds is planned for mid January. It will be held in London for his many friends, work colleagues and associates.
This article was first published on brandrepublic.com