Shares in French retail behemoth Carrefour rose sharply yesterday [Wednesday] on rumours that it was being courted by its larger US counterpart Wal-Mart.

As yet the rumours have not been substantiated, but shares nevertheless rose 4.1% to €42.77 (US$71.78) on an unusually heavy volume of 7.3 million shares.

An unnamed trader was reported by the Guardian as confirming that: “The rumour is that Wal-Mart are looking to buy Carrefour. There is nothing to confirm this but it’s affecting the price.”

A merger of the world’s leading retail, Wal-Mart, with second-placed Carrefour would doubtless prompt intensive investigations on the part of competition authorities.