Carrefour (Euronext: CA) shares fall as much as 7.6% after Canada’s Couche-Tard abandoned talks for a proposed $20 billion merger with the French grocer following stiff opposition from France’s finance minister. French Finance Minister Bruno Le Maire said that shooting down a foreign takeover bid for supermarket chain Carrefour SA last week was all about the politics. “Food security is non-negotiable” he said but did not clearly explain how such a deal could have an impact on French food supplies. Carrefour’s shares are 15% down form last Wednesday’s high.