The successful company - Laing Construction Wales and West Limited - was one of four shortlisted for contract.

Building work at the University Hospital of Wales in the city is expected to start in March.

Charlotte Church staged her first solo concert for the appeal

The appeal was launched in May 2000, with a target of raising £5m needed to build the first phase.

Once the money is raised, the Welsh Assembly Government will give a further £4.5m to complete the first phase of the hospital.

This will comprise three child-friendly wards, including a specialist cancer ward and much-needed family accommodation.

Singer Charlotte Church, the patron of the appeal, had been expected to unveil the design, but had to pull out owing to a television appearance commitment.

Noah's Ark Apeal trustee chair Lyn Jones said: "She did try up to the last minute to be here but she has to do these things.

"It's a bit of a disappointment but she has been a great supporter."

Campaigning

The cause has captured the hearts of people all over Wales including celebrities like actress Catherine Zeta Jones and former sportsman Ian Botham.

They took part in a marathon charity walk last year which alone raised £850,000.

Wales is the only European country that does not have a hospital specialising in the treatment of sick children.

Doctors and parents have campaigned for many years to establish a specialist unit in Wales.

The ultimate aim is to build a complete hospital which will replace existing facilities at the University Hospital of Wales in Cardiff.

The Ian Botham walk gave the appeal a real boost

The fundraising appeal has attracted considerable publicity.

In October, singer Darren Day handed over a cheque for £30,000, raised by taking part in a jungle celebrity survivor TV show, to help build a Welsh children's hospital.

The star was the third to be voted off by the public to leave the Australian bush during ITV1's I'm A Celebrity ... Get Me Out Of Here! in September.

He raised the money from the proceeds of the audience phoning and texting the show during the 10 days he survived the game, eventually won by DJ Tony Blackburn.

Day chose to back the fund after hearing about a family tragedy affecting his girlfriend Adele Ellicott, who is from Newport.

The 22-year-old former model's brother died when he was 11, a victim of a rare illness known as Sudden Death Syndrome.

Her family are keen supporters of the campaign for a children's hospital and are said to be touched by Day's choice of charity.