Update: Seems Newell made an incorrect slip of the tongue. Valve marketing vice president Doug Lombardi has since clarified to ShackNews that Left 4 Dead will arrive on North America shores November 18, with a European release following on the 21st. Lombardi cited “fine tuning” as the reason for the delay.

Speaking in an interview with German site GameKings, Valve president Gabe Newell revealed that the company’s highly-anticipated cooperative shooter Left 4 Dead will hit Steam and retail channels on November 20.

Previously scheduled for a November 4 release, the revised date will coincide with the tenth anniversary of Valve’s first game, the original award-winning Half Life. No reasoning behind the abrupt delay was given, though it was likely nothing more than a calculated marketing decision, given that Epic’s Gears of War 2 is slated to arrive on November 7.

Gabe Newell speelt Left 4 Dead [GameKings]

Read more: Left 4 Dead Demo Planned, Left 4 Dead Now Available On Steam For Pre-Order, Valve: Left 4 Dead Hitting PC, Xbox 360 In November, Valve Prepping Massive Left 4 Dead Ad Campaign, Valve Acquires Left 4 Dead Developer