Chelverton Investments, which owned London Broadcasting Company (LBC) until it went into receivership, has written to the Radio Authority claiming that the winner, London News Radio, has changed beyond recognition since the franchise was awarded even though it is not yet on the air.
It was announced last week that LNR, which bought LBC's assets, is to be taken over by Reuters Holdings.
Reuters originally formed part of the London Radio Company, an unsuccessful
applicant for the talk radio franchise.
James Morton, a director of Chelverton, said: 'There has been a complete change in the control and financial structure since the franchise was awarded. We believe there is a compelling case for the franchise to be re-advertised immediately.'
Chelverton, whose main investors include John Porter, son of Dame Shirley Porter, has asked the authority to reply within seven days, failing which they may seek a judicial review of the decision.
A spokesman for LNR said: 'The licence application will be followed to the letter with regard to the programming