In a dense, 110-page ruling issued on Wednesday, Southern District Judge Lewis A. Kaplan largely allowed a mammoth putative class action to move forward against Lehman Brothers’ directors, officers, auditor and underwriters.

Though he dismissed some claims, the judge singled out Lehman’s “Repo 105″ accounting gimmick and held that the plaintiffs had sufficiently alleged that Lehman officers and directors had misled investors.