Brunswick has bought SRU, the research company owned by social commentator Peter Wallis, better known as Peter York.
The deal, involving an undisclosed sum, provides Brunswick with a strategic and research-based capability to add to its existing advisory offerings.
Brunswick has worked closely with SRU since Alan Parker founded the PR agency 13 years ago.
Wallis, who co-founded SRU in 1974 with Lord Stevenson, now chairman of Pearson, said the consultancy would remain a separate entity and continue under the same name, although there is a possibility of co-location in the future.
'For Brunswick, the deal provides an instant in-house research capability.
For SRU, we are now part of a bigger international organisation with offices worldwide,' he said.