The third installment of Halo has launched in the UK following a celebrity launch party in London.

Spilt over two events at the IMAX cinema and bar 24 in Soho, Microsoft released Halo 3, which has become the biggest media entertainment launch in history, with competitions, giveaways and plenty of partying.

Not being put off by not being able to have an Oxford Street midnight launch opening due to fears of large crowds causing havoc on London's main shopping street, the event Kicked off at 5pm, seven hours to deadline, at the IMAX cinema in London at an event hosted by comedian Ian Lee.

Competition winners who had gathered from around the country keen to get their hands on the new game were invited to play against themselves and music star Pharrell Williams from N.E.R.D on the 4 storey high screen for a chance to win copies of the game.

As it was, in an attempt to not disappoint, everyone attending the party got a free copy of the game.

After the IMAX, the party moved north to 24 in Soho, a technically advanced bar complete with gaming screens.

Here, celebrities such as Sarah Harding from Girls Aloud, partied with the Master Chief until 3am.

Party-goers were given a copy of the game before they left.

Halo 3 is the biggest selling video game of all time with 1.5million pre-orders before launch.

The two previous outings have so far sold over 15 million copies between them.

>> Reviewed - Halo 3 - Xbox 360 Review