Britons party as London adopts host status

By Peter Griffiths and Kate Kelland

LONDON (Reuters) - Riding a wave of sporting euphoria after its best Olympic performance in a century, Britain accepted Olympic host-nation status from China on Sunday with a huge street party in front of Buckingham Palace.

As the Beijing games closed in a spectacular explosion of fireworks, London throbbed with 40,000 partygoers at a live concert to start the countdown to the London 2012 Olympics.

The event centred on The Mall, the ceremonial route to the palace used for royal processions and celebrations, which was lined on Sunday with red, white and blue Union Jack flags.

London Mayor Boris Johnson promised a "fantabulous Olympics" in 2012 as he accepted the Olympic Flag in Beijing in a live television link-up.

In a statement issued in London, the mayor promised Britons would "draw on our wit, flair, imagination and ingenuity" to deliver the 2012 Games in "the home of sport".

"Sport is coming home," he said. "See you in London!"

More than 400 flags were raised across Britain to mark the countdown -- from Land's End, the tip of southwest England, to the northernmost Unst island, off the Scottish coast -- and BBC television started an on-screen countdown clock showing 1,433 days to go.

Boy band McFly, and singers Katherine Jenkins, Will Young and James Morrison were among artists performing at the party.