Meanwhile UK media watchdog Ofcom has approved ITV's plans to cut its non-news regional programming.
With audiences for its flagship channel ITV1 sliding, the UK's largest commercial broadcaster, ITV, faces further ratings woes as its state-owned but commercially funded rival Channel 4 gains in the race for younger viewers.
Latest figures from BARB (Broadcasters Audience Research Board) indicate that in the six months to date this year ITV1's share of the key 16-34 age group has fallen from 21.3% in 2004 to 17.9%.
In comparison, Channel 4's ratings for the same demographic rose from 11.6% to 12.7% during the same period. Overall, the figures show Channel 4 just five percentage points behind ITV1. Last year it was around 10.
Audience fragmentation has partly contributed to ITV's decline, but Channel 4 has also won more young viewers with US imports such as Desperate Housewives and perennial favourite Big Brother, together with its spinoffs.
ITV, however, maintains a publicly bullish stance, claiming its "digital family" attracts young viewers. Avers a spokeswoman: "To put these latest figures in context: in the same period last year, ITV1 transmitted its most successful ever series of I'm a Celebrity, Get Me Out of Here!, one of our highest ratings shows amongst 16-34 year-olds."
She added: "So far this year Channel 4 has already used the big guns of Celebrity Big Brother and Desperate Housewives to boost its share for this demographic."
The broadcaster is hoping the reduction in its public service broadcasting obligations will allow it to compete more effectively in the expanding digital market.
In the English regions ITV's minimum PSB requirement will be cut by half to 90 minutes per week. However, in Scotland, Wales and Northern Ireland, airtime will have to be found for four hours of PSB shows each week, to be gradually reduced as regions switch to digital-only broadcasting.
The BBC has agreed to fill the gaps left by ITV by taking "the lead in services for the [semi-autonomous UK] nations and English regions, as ITV1's presence and obligations are reduced".
Data sourced from MediaGuardian.co.uk; additional content by WARC staff