Mobile phone group Orange announced it had made a post-tax profit but the results were overshadowed by problems at its parent France Telecom.

France Telecom's chairman Michel Bon resigned after a troubled time at the heavily-indebted group.

His resignation came as France Telecom released details of its interim results, showing losses of £7.6 billion.

The group, which is 55.5 per cent owned by the French government, has been battling against spiralling debts and a plunging credit rating.

France Telecom is also ending its financial support for troubled German operator MobilCom, which could file for bankruptcy protection.

Analysts said France Telecom's troubles meant the group could sell part of its stake in Orange to reduce debts.

France Telecom owns more than 85 per cent of Orange. It bought the UK business two years ago and floated a small percentage in February last year.

Chavan Bhogaita, analyst at Bear Stearns, said: "Orange could feature in France Telecom's plans in terms of debt reduction. Options could include selling part of its existing stake in Orange or even an mmO2-style demerger (mobile group mmO2 was demerged from BT)."

The concerns came as Orange made its first post-tax profits, before exceptional items, of £138 million.

Chief executive Jean-Francois Pontal said the profit, for the six months to June 30, was another financial milestone for the group.

The figure compared with losses of £316 million last year and the profits came 18 months ahead of the group's forecast.

But writing down the value of its 26.6 per cent stake in Italian operator Wind by £696 million meant bottom-line figures were pushed into the red.

Losses came in at £546 million against £316 million last time.

The upbeat figures meant the group raised its profits targets for this year.

It expects earnings to come in ahead of previous forecasts and funding needed to be less.