The BBC Trust has blocked the broadcaster's plans to make its iPlayer software a standard. The Adobe Air application has become increasingly popular in the UK and overseas, by offering users a way to watch and download BBC TV and radio programmes over the internet.
The BBC had proposed that ITV, Channel 4 and Channel 5 should have access to iPlayer to enable them to compete with other TV companies when the UK switches over to digital TV in 2012.
However, the BBC website has reported that the trust did not feel that sharing the iPlayer would not deliver value to licence-fee payers.
Last week Channel 4 announced it would make its programmes available free of charge on YouTube.