LONDON: The UK's commercial television broadcasters are facing a bleak September with the advertising market forecast to shrink by around 10%.

A consensus of media buyers is predicting an ad revenue slide of around 13% to £118 million ($233m; €148m) at ITV1, the flagship channel of Britain's biggest commercial broadcaster.

ITV's secondary channels are expected to fare rather better and are likely to see a year-on-year rise of around 8% in ad revenues in September.

But media buyers fear the overall negative outlook for the total TV ad market in September - following forecasts of 1% and 4% declines in July and August respectively - signals a gloomy final quarter.

Publicly owned but commercially funded Channel 4 is predicted to see revenues at its flagship channel slide 13% year-on-year in September, to around £59m. But its digital portfolio, including E4, is likely to be up 6% year on year to £15m.

The smallest of the commercial broadcasters, RTL-owned Five, is expected to be down around 9% year on year in September with circa £27m in ad revenue.

The overall TV advertising market is predicted to be down 4% during 2008, compared with 2007.

Data sourced from; additional content by WARC staff