The studio behind the S.T.A.L.K.E.R. series of first-person shooters is no more, according to online reports.Ukraianian news site UkraNews reports [Russian language] reports that the owner of Ukranian developer GSC Game World, Sergei Grigorovich has decided to shutter the studio, promising to pay employee wages through February 2012.Studio director Dmitri Bourkovski seemingly reinforced the report via a recent tweet [Russian language], which translates to, "Not PR. GSC closed."The studio's closure also means the end of development for GSC Game World's upcoming, the fourth release in the cult PC shooter series.Gamasutra has contacted GSC Game World for comment, but has yet to hear back as of press time.GSC Game World was originally founded in 1995, and before releasingin 2007, the company developed PC titles such as, andIn 2006, a group of GSC veterans left the company to found 4A Games, the studio behind the 2010 post-apocalyptic shooter