Late last week, sharp-eyed internet surveyors noticed that Grand Theft Auto 4 had suddenly, without warning, been delisted from Steam. With no official explanation, fans were left to speculate on the reason for the move, but now Rockstar has spoken, pointing the blame finger squarely in the direction of Microsoft's now-defunct Games for Windows Live.
In a statement provided to USgamer, Rockstar explained it was forced to suspend sales of GTA4 on Steam simply because it's now "no longer possible to generate the additional keys needed to continue selling the current version of the game", given that Microsoft has officially ended support for the Games for Windows Live platform baked into the title.
Although this means Grand Theft Auto 4 is unavailable for purchase on Steam at present (standalone expansion Episodes from Liberty City is unaffected), Rockstar says it's "looking at other options for distributing GTA4 for PC".