It’s a stunning acheivement for the critically-acclaimed shooter, which has become a firm fan’s favourite online.

“We’re delighted with the performance of COD4,” said Activision marketing director David Tyler. “It’s been exceptionally well received by both consumers and retail. It’s a great start to 2008 and we’re all looking forward to launching some amazing new titles in the forthcoming months.”

The news comes as the UK operation is bolstered by the arrival of two key marketing staff.

Joanne Nicholson previously worked as a product manager at toy giant Character Options where she was responsible for a portfolio of girls’ and pre-school brands, including Disney Princess, Gr8 Gear and Barney & Friends. She joins Activision as brand manager for kids and superhero titles.

Simon Wells joins the publisher as brand manager for core games, covering the key Call of Duty and Quake franchises. Wells previously held roles at Vivendi and Eidos, working on popular products such as World of Warcraft and F.E.A.R.

“We are pleased to have Simon and Jo join the UK marketing team,” said marketing director David Tyler. “Our brand strategies and marketing programmes have been integral to achieving huge commercial success on many of our recent titles. Simon and Jo will both be significant contributors in driving our brands even further in 2008.”