Grand Theft Auto V has the potential to be the biggest launch of the generation, GfK Chart-Track says.
The fastest selling game of all time in the UK is Call of Duty: Black Ops, which sold 2m units in its first week.The game that made the most money after its first week was Call of Duty: Modern Warfare 3, which made 83m.
But Chart-Track would not be surprised if GTA V beats both of those figures.
"Many people have forgotten the effect GTA IV had on the market back in Q2 2008," said Chart-Track director Dorian Bloch.
"It sold just under a million units in its first week – only four Call of Dutys and one FIFA game have done better. More impressive still is the fact that it sold to almost one-third of the entire PS3/360 installed base at that time, in just 1 week.
"It won't achieve that level of penetration week on4 this time, but it has the potential to reach the week on3 summit, which is currently 2m units of Black Ops / 83m for Modern Warfare 3."