BSkyB, the parent company of Sky News, has turned down an approach from Rupert Murdoch's News Corporation to take full control of the company.

News Corp, which currently owns 39% of BSkyB, wanted to buy the remaining shares for 700p each.

BSkyB rejected the proposal, saying it undervalued the company, but added that its independent directors would be prepared to support a bid offering in excess of 800p per share.

The news sent BSkyB shares soaring by up to 20%, their biggest jump in a single day for more than a decade.