The 'Cold Stream' add-on launches on Friday, August 3 for 560 Microsoft Points (£4.80/$7).
"We are set for the title update and the Cold Stream DLC to be released this Friday," reads a Valve tweet.
Released as a free update for PC and Mac users last week, the pack contains the fan-made 'Cold Stream' map, as well as updated versions of 'Crash Course', 'Death Toll', 'Dead Air' and 'Blood Harvest'.
The update also grants permanent access to all mutations, such as 'Lone Gunman' and 'Last Man on Earth'.
In order to access the mutations, however, Xbox 360 users must already own 'The Passing' DLC.
Left 4 Dead 2 was released in 2009 as a follow-up to the original Left 4 Dead, which launched in 2008.
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Watch the Left 4 Dead 2 opening cinematic below: