Google today announced it is rolling out click-to-play video adverts in the UK, a move designed to up the already intense pressure the internet advertising leader is placing on traditional television networks.

In what will seem a counter-intuitive strategy to many consumers used to dodging adverts on conventional television stations, the new Google ads, which have already been piloted in the United States, Canada and Japan, will only begin playing when a user clicks on them.

"To protect the user experience, click-to-play video ads are user-initiated. As a result, advertisers get more engaged users and qualified leads," Google said.

The move comes as Google battles to increase its share of the overall advertising market. While online advertising is growing rapidly, it still only accounts for a small portion of total marketing spending.

Broadcast and cable TV advertising in the United States will be worth approximately $38 billion this year, according to Universal McCann, a prize on which online groups including Google and rivals Yahoo and Microsoft are firmly focused.

In part, internet companies are banking on advertisers being drawn away from TV through the high level of targeting possible through online video ads.

Google’s click-to-play video ads can be targeted to specific sites or contextually. Pricing for click-to-play video ads can be either cost-per-impression or cost-per-click, Google said.

Users who want to view the adverts press "play" on the control bar at the bottom of the advert window to start the video. Advertisers will be able to measure the effectiveness of their video ads by tracking video play-back rates, click-through rates to their destination site, as well as how long users play a video.

The ads will be triggered to appear on third-party web pages covered by Google's AdSense system.

The service is designed to diversify Google away from the simple text-based ads that account for the bulk of its revenues. Last week the company launched its online video service, Google Video in the UK.

For examples of how Google's new adverts work click here.

Times Recommends

• Lies and cover-up at MG Rover exposed by report
• High oil prices push manufacturing costs up
• Primark founder steps down as chief executive