The BBC is to increase its annual spending on programmes for the Welsh-language channel S4C, and produce more of them under a new agreement.
Long-running soap Pobol Y Cwm is produced by BBC Wales
The announcement follows the UK government White Paper on the future of the BBC published earlier this year.
Spending will rise by £3m to just over £25m by 2008/9 as part of the new strategic partnership.
The agreement will also make BBC Wales programmes available on S4C's broadband and on-demand services.
BBC Wales controller Menna Richards said the agreement gave the best chance of "strengthening and extending Welsh language services".
At present, the BBC has a statutory duty to provide S4C with more than 10 hours of Welsh programming made by BBC Wales each week.
It has supplied programmes like the soap Pobol Y Cwm ever since the channel was launched in 1982, and also makes the news programme Newyddion.
However, until now S4C had little say over what the corporation provided.
The new deal means the broadcasters will work more closely together on planning Welsh-language television.
A number of new programmes will be launched to help S4C fill gaps when English-language programmes disappear from the channel completely when the switchover to digital happens in Wales in 2009.
BBC chairman Michael Grade said: "We are delighted that this new partnership will strengthen and extend the BBC's contribution. I'm certain Welsh-language audiences will reap the benefits."
S4C chairman John Walter Jones said: "The new partnership provides a welcome new chapter in the relationship between S4C and the BBC.
"We are grateful to the BBC for the extensive support enshrined in this settlement."
The latest timetable for digital switchover has been published, with Wales given the dates when its traditional analogue signal will be turned off.
Wales will switch in three phases: the south and south-west between July and September 2009, the north-west and north-east between October and December 2009, and the rest between January and March 2010.