UK retail giant HMV is expecting Activision's newly-released first-person shooter, Call of Duty: Modern Warfare 2, to become the fastest-selling game in UK history and predicts that it will sell over 1 million copies in its first week on sale.

The entertainment chain, which opened 140 stores at midnight last night to sell the game, believes that the Infinity Ward-developed game will eclipse the 800,000 week one sales record set by Grand Theft Auto IV last year.

"Modern Warfare 2 raises the bar for all games, not only for the astonishing demand we are seeing from gamers all around the country, but for its technical brilliance also," said HMV's Gennaro Castaldo. "With more than a million unit sales likely in its first week alone, HMV confidently predicts it will go on to become the biggest-selling title ever in games history."

The game has seen huge online pre-orders, the company said, while discounting at some supermarkets have resulted in a large number of them sell out, with Activision working now to re-stock.