People living in Northern Ireland will be able to access RTE and TG4 via Freeview for the first time by 2012.
The deal between the UK and Irish governments also includes greater access of BBC services in Ireland.
Minister for Broadcasting Jeremy Hunt said the move had be based on a commitment as part of the Good Friday Agreement.
"A memorandum of understanding was signed committing us to working together on the technical arrangements"
The move is expected to come into affect ahead of 2012 when analogue services are switched off in Northern Ireland.
In 1998 the UK government explored the possibility of achieving more widespread availability of the Irish language television station TG4 across Northern Ireland.
Previously TG4 was available on a free-to-air basis to about 60% of the population in Northern Ireland.
The UK and Irish governments have now agreed that the most effective way to provide for the continuing provision of TG4 is by building a new 'band' which is a means of carrying the channel.
In addition to carrying TG4 it will also carry RTÉ1 and RTE 2.
It is hoped that this will increase the coverage of these channels in Northern Ireland, enabling about 90% of the population to receive the services on Freeview.
Up until now people living in Northern Ireland either had to have a special satellite installed or subscribe to Sky digital to access the channels if they were not in an area covered by the analogue signal.