Analogue television will start being phased out from 2008

The BBC's channels, ITV1, Channel 4 - S4C in Wales - and Five are among those due to reach 98.5% of the UK, under the agreement with neighbouring countries.

But 10% of viewers will not be able to receive all Freeview channels.

Countries agree sites of transmitters, and the frequencies and strength of their signals, to avoid interference.

Availability of 98.5% would mean digital TV reaching about the same percentage of viewers as currently can watch analogue TV through aerials.

But only 90% will be able to receive the full Freeview service, which currently comprises more than 30 TV channels, with public service channels taking priority.

QUICK GUIDE Digital switchover

Analogue TV transmissions will be switched off as part of the UK's digital switchover scheme, which begins in 2008 and ends in 2012.

At present, only 73% of homes can get the Freeview digital service through their aerials.

International deal

Media watchdog Ofcom led the delegation that secured the agreement at an international conference.

The UK's plans required successful negotiations with France, the Netherlands, Belgium and the Republic of Ireland among others at a conference in Geneva.

"This accelerates the move to all-digital broadcasting," said Ofcom chief executive Stephen Carter.

"After months of detailed negotiations involving more than 100 countries, this successful outcome is testament to the hard work and dedication of the UK delegation."

Agreements were also reached on UK plans for the expansion of digital radio.

It was announced last month that Freeview had become more popular than analogue TV, with almost 7.1 million households now using Freeview on their main set compared with 6.4 million still relying on analogue.

Some 18 million homes now watch some form of digital television.