Halo 3 has become the fastest-selling Xbox 360 game in the UK, according to monitoring company Chart-Track.

However, the fastest selling game of all time, and record holder for week-one sales, still belongs to the PlayStation 2 release of Rockstar's Grand Theft Auto: San Andreas in 2004.

Chart-Track pointed out that, having been around for four years, the PlayStation 2 installed base was around 6.6 million in 2004, while Microsoft's Xbox 360 has reached 1.4 million in under two years.

Over 466,000 copies of Halo 3 were sold in the first four days after release, and the game was bought by one in three Xbox 360 owners in its first week. Just one in 10 PlayStation 2 owners bought GTA San Andreas in its first week.

Despite the hype and media coverage surrounding the launch of Halo 3, Microsoft was not the only winner this week.

Electronic Arts recorded the best ever opening weekend for its long-running football series with the release of Fifa '08.

Halo 3 and Fifa '08 accounted for 83 per cent of Xbox 360 game purchases last week, taking the number one and two spots away from Tiger Woods PGA Tour '08 and MySims, which dropped to third and fourth positions respectively.