The overwhelming majority of mergers and acquisitions fail to fully achieve the objectives that drove the deal in the first place, according to research by global management consultancy Hay Group.

The research found that 97% of UK mergers and acquisitions fail to achieve their strategic objective, with the most common reason the culture shock that comes when two companies join together. This compared against a European average of 91%.

Well under a third of such deals (28%) said the move had created significant new value, which will be of concern to those involved in such activity during the acquisition boom of 2006-7.

“Integrating intangible assets six months after a deal has gone live is too late,” said David Derain, a director at Hay group. “Companies should be examining the compatibility and differences between the two firms well before the deal is made public, in order to have a clear plan of action in place right from the start.”