The deadlock in Franco-American discussions over the role of Crédit Lyonnais in the Executive Life scandal is threatening to extend to the US activities of Crédit Agricole, France's largest retail bank.

People familiar with the negotiations said the US banking licence of Crédit Agricole could be at risk, even though the bank had not yet fully integrated the US operations of Crédit Lyonnais, the privatised bank it acquired for €19.5bn ($23.6bn) earlier this year.