The parlous state of British commercial television was underlined today when Channel Five's German parent company RTL slashed the value of the broadcaster by €337 million (£314 million).

RTL blamed a "significant slowdown" in TV advertising and the "increasingly fragmented UK television market". Chief executive Gerhard Zeiler said Five's UK rivals were also suffering. ITV last week wrote down the value of its TV and online operations by £2.7 billion.

RTL said annual group profits slumped to €194 million from €563 million a year earlier, chiefly because of the Five writedown.

Five lost £2 million in 2008 after a £7 million profit a year earlier, but revenue held steady at £341 million.

The main Five channel was profitable but earnings halved to £12 million - partly because it spent heavily on signing up Australian soap Neighbours and newsreader Natasha Kaplinsky. Restructuring and losses at digital channels tipped it into the red.

Profits at sister company Fremantle Media jumped 18% to €155 million.