The screen is the third to be erected in the UK

It is hoped the screen will turn Clayton Square into a free live entertainment venue, creating a unique outlet for local artistic talent.

It is the third, and biggest, BBC Big Screen to be erected in the UK.

Test transmissions are under way, and it is due to be fully operational by the start of the Olympics.

Big Screen manager Bren O'Callaghan said: "This will transform Clayton Square into a hub for live entertainment, whilst visitors to the city will be able to look upon a digital window that boasts an overview of the entire region.

The screen towers over shoppers on Clayton Square.

"Most importantly, the screen is a unique means of championing local, creative talent - from filmmakers, artists and DJs to schoolchildren, community groups and unsigned bands."

In addition to the video content there will also be a city diary listings service and a ticker updated with the latest news, sport and entertainment headlines.

The first permanent BBC Big Screen was unveiled in Exchange Square, Manchester, more than a year ago and has proved a big hit.

Another has since opened in Birmingham and seven more are planned across the UK over the next three years.

The Liverpool project is a joint venture between the city council, the BBC, sponsors RBS and manufacturers Philips.