Cossette approached a number of potential acquirers after Cosmos made an unsolicited approach to buy the company in July. Those firms have been granted access to “an extensive electronic data room” but Cosmos has been excluded from the process “on the advice of the financial and legal advisers of the company”.

Explaining the decision today, Cossette said its special committee had considered “the unfair imbalance of knowledge held by Cosmos relative to other potential acquirers” because of the participation of Duffar (pictured) and Georges Morin, a former director of Cossette who is part of the Cosmos bid.

“A level playing field, in terms of equal access to confidential information, is essential to achieve a process that maximises value for shareholders,” the company said.

Cosmos has offered C$4.95 per share to buy Cossette. Lock-up agreements with other shareholders and its own holdings mean more than 30% of shares are already committed to the deal – at least in the absence of any higher-priced offers for the company.

Cossette says other potential bidders have been invited to submit written expressions of interest in making an acquisition. The group provides strategic planning and research services through its agencies Nucleus and Impact Research in Canada, Cossette in the US and Miles Calcraft Briginshaw Duffy in the UK.