"This is an exciting time for us," said Millennium Stadium chief executive Paul Sergeant. "We cannot over-state the value of the curtain system. The original design of the stadium with its retractable roof and removable pitch has been a blessing, but this new concept will unlock the door to a whole new world for us.

"Hosting some of the biggest football games in the UK calendar has really put us on the map in sporting terms. But football is going back to Wembley and the Arena means we are available to so many more ideas, configurations and solutions for possible events."

A £1million investment in the joint venture by the Millennium Commission, host caterers Letheby and Christopher, the Wales Tourist Board and the Millennium Stadium has seen the installation of a 60 x 40 metre modular stage, 17 sections of partition drape and an independently suspended lighting grid. This allows the main bowl to be cut into four possible staging configurations to accommodate events with audiences of between 12,000 and 46,000.

The Millennium Stadium is a Millennium Commission project and has backed the Arena concept from the outset. Director of the Millennium Commission, Mike O’Connor CBE said: "The Millennium Stadium has captured the imagination of spectators and players alike.

"The new Millennium Arena is a very exciting addition to the Stadium and will add to its international reputation as a first class venue. We are very proud to have invested £46m of Lottery money in this magnificent Welsh achievement."

The grid and drape system produces a veritable ‘arena’ under the closed roof of the Millennium Stadium – making the Millennium Arena the largest indoor venue of its kind in Europe. The revolutionary design has an unrivalled level of flexibility so the capacity of the arena can be altered considerably according to the requirements of the event owner or promoter, undoubtedly causing an upturn in Cardiff’s ability to attract events. This was one of the reasons the Wales Tourist Board backed the initiative.

Chief executive Jonathan Jones said: "The Board was delighted to be able to make a substantial grant of £99 000 towards the cost of the scheme that will allow the Stadium to stage events that draw a range of audiences lower than full Stadium capacity.

"This will enable the Millennium Stadium to operate all the year round, thereby raising its revenues and increasing its contribution to the local economy."

The Arena’s maximum capacity will surpass that of Wembley Arena (11,500), Birmingham’s NEC (13,000), Manchester’s MEN Arena (21,000) and the Earl’s Court Centre (22,000), and will offer music promoters, conference, banqueting, festival and trade show organisers, sporting bodies and theatre and cultural groups the chance to pick the size of their arena. And it is this new versatility which Stadium caterers Letheby and Christopher agree is the unique selling point of the idea.

"As a company that has invested in the Millennium Stadium right from the start, we believe this new facility will help the Stadium become a truly multi-faceted arena which will accommodate a great many more events throughout the year," added Managing Director, Stadia, James Murphy. "It will be essential for the Stadium’s success when football returns to Wembley, bringing new business to Cardiff."

The Millennium Stadium is already renowned as a sporting citadel as the home of Welsh rugby and has become a true home of club football over the past five years while Wembley is being built. It is also well respected for its ability to turn around and stage major concert events, especially the recent Tsunami Relief Cardiff concert, but also as an established venue for major concert tours such as this week’s Cardiff leg of the U2 Vertigo tour and the Red Hot Chilli Peppers. But now, there are even more exciting times on the way for events at the Cardiff venue.

The list of potential events is huge – concerts ranging from rock, pop, jazz and classical, live sport such as tennis, boxing, basketball and entertainment events such as ice skating and wrestling. Other attractions will be the ability to host major award ceremonies and banquets, presentation evenings and conferences – the arena will have the ability to be the largest conferencing and exhibition centre in the UK. In short, there is no limit to the possibilities.