Mr Trujillo's departure comes as a complete surprise

Though described by Orange as part of a "wide-ranging re-organisation" interviews with Mr Trujillo would indicate otherwise.

Last October he expressed frustration at his lack of independence at Orange, in a Reuters interview.

Orange as a separate company had grown aggressively under Mr Trujillo.

People close to the chief executive said his views often sat unhappily with other board members at France Telecom. He once announced publicly that France Telecom should be rebranded as Orange.

The exact reason for his departure is still unclear. Mr Trujillo had earlier denied rumours that he had plans to leave, while Orange's official announcement of the news fails to give a clear reason for the change at the top.

Orange's new boss will be Sanjiv Ahuja, currently the firm's chief operating officer.

The vast majority of Orange shares are held by France Telecom, which adopted the name of its UK subsidiary as the global brand for its mobile phone operations.

Orange has some 30,000 employees and more than 45 million subscribers in France, the UK and 18 other countries.mainly in Europe.

France Telecom is currently in the process of buying up the remaining shares of Orange's minority shareholders, a process the company now says it hopes to complete by the end of April.

Tasked with integration

Sanjiv Ahuja takes charge at Orange

France Telecom chairman Thierry Breton praised Mr Trujillo, saying he had done "an outstanding job at Orange", turning the "federation of companies" into a "unified organisation".

Mr Trujillo in turn was quoted as saying that he was proud of bringing together a team that had managed to give Orange "the structures and organisation it lacked".

The top priority for Mr Ahuja will be the integration of France Telecom with its mobile subsidiary, a task Mr Trujillo had been brought in to oversee.

Mr Ahuja's appointment also means that Europe's two largest mobile phone companies are now run by Indian-trained engineers.

Last year, Arun Sarin became the chief executive of Orange's rival Vodafone. Mr Sarin graduated from the famous Indian Institute of Technology, while Mr Ahuja graduated from Delhi University.

As part of the reorganisation, three top Orange executives will join the France Telecom board - Mr Ahuja, joined by the bosses of Orange's UK and French operations, John Allwood and Didier Quillot.

France Telecom will also merge its internet division Wanadoo with its fixed-line telecoms business.

As a result the company will effectively be focused on two areas - mobile phones, and broadband and telephony.

Mr Trujillo came to Orange from American telecoms operator US West, where he had been chief executive. At the time of his appointment he was seen as a surprise choice.