Mr Caudwell, who had considered selling the empire — which includes more than 350 Phones4U high-street retail outlets and the Caudwell Communications fixed-line business — in parts is now seeking instead to secure a one-off windfall.

It is understood that the company believes it can secure up to £2 billion for the business, in which Mr Caudwell is an 85 per cent shareholder.

However, some industry insiders suggested that the valuation was “unrealistic” based on the size and scope of the business.

Mr Caudwell said that he had decided to sell the group, which employs 8,500 people, because the “mobile sector is booming and everyone wants to get into it. It is a great time to sell”.

He said that he wanted more free time to fulfil ambitions such as sailing the world and spending more time on charity work.

The 52-year-old billionaire, who founded the group as Midland Mobile Phones in 1987, said that he was also in talks over a new venture in America. “I am negotiating about a project in America — a new business that is associated with the leisure sector,” he said.

The sale of the Caudwell Group, which makes most of its revenues through its Phones4U mobile retail outlets, comes after the recent sale of O2, the British mobile operator. O2 agreed an £18 billion offer from Telefónica, the Spanish telecoms giant.

Several other telecoms players are on the market, including onetel, part of Centrica. Your Communications — a provider of corporate telecoms services and part of United Utilities — has said it is considering a sale.

Mr Caudwell, the former owner of a car repair business, is not shy of publicity and is regarded as one of the more colourful characters in the telecoms industry. He lives in a £10 million, 65-room, Grade I- listed mansion in Staffordshire.