Director Sam Raimi along with stars Tobey Maguire and Kirsten Dunst will not be involved with Sony Pictures fourth installment in the Spiderman film series.  As reported in LA Times, Sony pulled the plug on the project in its current form after Raimi informed the studio that he could not complete it based on current schedule and budget.  Maguire and Dunst revealed that they were bowing out shortly after studio and director announced their decision to part ways.  The film had seen preproduction delays as it moved hands among four different writers said to be struggling to bring together a workable script.  Despite the delay, Sony had informed Raimi that it expected the film to make its summer 2011 window.  The studio had also requested that the film cost around $230 million, significantly less than the estimated $300 million Raimi spent on  Spiderman 3.   Sony now says it will reboot the franchise with a film in 2012 based on character Peter Parker s youth.  LA Times says the shift leaves a hole in Sony s summer 2011 schedule.  The outlet further reports that Paramount s release date for action film Thor has been moved up three weekends to take the May 6, 2011, window originally planned for the Spiderman sequel.  Read more at LA Times.