Sales of the most recent CoD are 4.2 per cent behind where Black Ops was in the same period.
This year's Call of Duty game will be Black Ops 2, a sequel to 2010's hugely successful title from Treyarch, according to leaked information posted on the official Black Ops forums.
This year's Call of Duty game - could it be Call of Duty: Black Ops 2? - will see "meaningful innovation" for the well-worn FPS juggernaut, Activision has said.
Call of Duty Modern Warfare 3 failed to match up to the UK sales record set by 2010's Call of Duty: Black Ops, according to data released by ERA.
FPS titles dominate Microsoft's listings for the most-played games on Xbox LIVE for 2011, with Call of Duty titles occupying the top three slots.