Treyarch's wartime shooter Call of Duty: World at War has more than doubled the week-one UK sales of Infinity Ward's Call of Duty 4, GamesIndustry reports.

World at War arrived at retailers last week, hitting two more platforms--PS2 and Wii--than Call of Duty 4: Modern Warfare, which was released on PC, PS3, Xbox 360 and Nintendo DS. The PS2 edition of CoD:WaW was developed by Rebellion, while n-Space handled the DS editions of both CoD4 and CoD:WaW.

As GamesIndustry and UK sales-tracking firm GfK Chart-Track did not provide a specific per-console breakdown of World at War's sales figures, the effect those additional platforms had on its retail performance is not yet known.

After Infinity Ward created the first two Call of Duty entries, Treyarch was brought on to co-develop the series as part of publisher Activision's "leapfrog strategy" for annual releases. Treyarch handled Call of Duty 3 while IW prepped CoD4, with the series creator presently working on Call of Duty 6 for a 2009 release.