France’s ruling centre-right party is to call for an investigation into how France Telecom amassed one of the world’s biggest corporate debts.

Share prices were higher in midday trading, lifted by a tentative round of bargain hunting after heavy selling seen last Thursday and Friday, although Axa underperformed as investors fear a recent string of capital increases by European insurers could signal similar moves for the rest of the sector, dealers said.

Four other members of France Telecom's 21-strong board stood down in solidarity with chairman Michel Bon, who tendered his resignation to the government.

France Telecom has set out the details for the flotation of Orange - and depressed the market in doing so.