Google is set to overtake British television channels as the largest recipient of advertising revenue, according to reports today.

Andy Duncan, chief executive of Channel 4, told The Times that Google would earn about #900 million in revenues this year compared with #800 million at the C4 group, and he warned that measures need to be taken to protect broadcasting.

The search engine generated #373 million in revenues in the fist six months of this year and is on track to generate #824 million for the year.

"People need to wake up and realise that this is not just a cyclical issue - there is deep structural change, rather like global warming," Mr Duncan told the paper.

"If we want to protect the fantastic legacy of UK broadcasting, we need to wake up to this sooner or later."

Channel 4 is concerned it may not be able to generate enough money to invest in high-quality programming.