The BBC has officially announced the sale of its commercial subsidiary BBC Broadcast by placing advertisements in the national press.

The sale, which is subject to approval by the BBC board of governors and Tessa Jowell, the Secretary of State for Culture, Media and Sport, is expected to be completed by the summer, with the division carrying a £100 million price tag.

The formal sale announcement comes just days after Ms Jowell launched her broadcasting Green Paper, in which the BBC governors are to be replaced by two new bodies.

Possible candidates to buy the company, which is operated on a commercial basis and has a turnover in excess of £100 million include Thomson, the French technology group; Ascent Media, a TV production specialist owned by Liberty Media; Carlyle, the venture capitalist; and Macquarie Infrastructure Communications Group, the owner of the NTL television transmission business.

The public broadcaster, which has refused to use an investment bank to advise on the disposal, is expected to draw up a list of interested parties shortly after Easter. Only then will the bidders receive full details of the unit's financial performance.

BBC Broadcast employs 1,000 staff and carries out three distinct services: handling channel promotion and branding, subtitling and "play-out" - the process of broadcasting a channel.

The unit, which made an operating profit of £7 million last year, is being sold as part of a corporation-wide rationalisation exercise conducted by Mark Thompson, the director general.

Mr Thompson decided that, while the services provided by BBC Broadcast are vital to the BBC, they did not necessarily need to remain owned by the corporation.

BBC Broadcast will continue to work closely with the corporation after the sale.

The BBC said a new owner would provide the business with new opportunities for growth, which are not available while the corporation owns it. The company will benefit from the stability of a seven-year contract with the BBC, the corporation added.

"The BBC has a great relationship with BBC Broadcast and we are committed to finding a long-term partner that can not only continue to deliver the outstanding quality of services back to the BBC, but also help BBC Broadcast continue to develop in new markets," Peter Phillips, the BBC’s director of business development, said.

"Staff issues and the right cultural fit will also be an important part of this deal."

The BBC said it will be in full consultation with the unions throughout the process.

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