Assassin's Creed 4: Black Flag Articles for Xbox 360On: Xbox 360, PS4, Xbox One, PS3, PC, Wii U £44.86 Buy Now
Is only the third biggest launch of 2013, behind GTA 5 and FIFA 14.
Outsells PC and Wii U versions, too.
Big IPs see massive decline in opening week sales, industry site reveals.
But neither game could match sales of Assassin's Creed 3 and Battlefield 3.
Uplay Passport to be terminated.