The big screen is being used to provide a mixture of live television and local information in text form including news and weather updates. The system will operate 24 hours a day and throughout the year long. A team of pilot researchers will study how people in a public place respond to various uses of the screen.

The state of the art technology will be used to show a wide range of televised events including news, sport, entertainment, art and community projects over the next year. The first major event to be featured is live action from the FA Cup (17 May), followed by the Manchester Festival Europa (22 May to 1 June) and the Eurovision Song Contest (24 May).

The screen will be operated by the BBC from its Manchester base in Oxford Road. It will have its own schedule drawn from a mixture of live BBC television programmes, relays of live events in Exchange Square, locally produced films and videos and a continuous feed of local information from BBCi.

The Beeb is providing the programming and creating the schedule in conjunction with the other stakeholders. Consumer electronics major Philips will be providing the equipment, installing the screen and maintaining its supporting technology.

As part of the opening ceremony which is scheduled to take place this evening aerial artists Viva will hang from cranes over Exchange Square to unveil the screen. The performers are famous for their red silk acrobatics which are shown regularly between BBC One programmes.

BBC director of nations and regions Pat Loughrey said: "It offers a new way to deliver quality programming and major events to our audiences and at the same time to provide an innovative new facility for Manchester. We have high hopes for it."

Chairman and chief executive of Philips Electronics UK, David Jordan said:"Philips has done more to develop the television set over the years than any other company. Taking the TV set out of the living room and making it a focal point in large public spaces where people can gather in this way shows what an important part TV plays in our daily lives."

"Today we have moved another step forward by helping to take broadcasting into public areas where people can enjoy the atmosphere of getting together whilst being able to view high quality television coverage," Jordan adds.