The commercial broadcaster announced in September that the Freesat service aimed to be operational by June.
But continued high sales of digital terrestrial Freeview boxes is understood to have prompted a rethink by ITV executives in recent weeks. This week, the Freeview consortium, which ITV joined in October, will announce that sales have broken through the 10 million mark.
Now, it is likely that the subscription free service will become available sometime next year because ITV wants to concentrate on marketing the Freeview service instead. ITV has higher ratings in Freeview homes than those with Sky television.
Asked if the service would launch in the first half of the year, a spokeswoman for the BBC said: "Obviously, it's not going to happen that quickly. It might be available at the end of the year, but timings [can] change."
The Freesat service is aimed at the estimated 25 per cent of UK households which cannot receive a digital terrestrial signal. When the service was unveiled, only BBC and ITV digital channels were signed up.
Broadcasters are embroiled in a land grab for households which have not yet decided on a digital service. The Government will start to switch off the analogue signal in some areas in 2008, with complete analogue switch off set for 2012.
Around seven million homes have Freeview, with around one million boxes being sold over Christmas. Sky has close to eight million customers. Cable has just under four million television customers, leaving five million homes without any type of digital television.