F.2d 923, 926 (9th Cir.1990). This distinction between core and noncore matters ensures that the bankruptcy courts will not encroach impermissibly in the province reserved by the Constitution to Article III courts. Mankin, 823 F.2d at 1300-07 (discussing Northern Pipe Line Constr. Co. v. Marathon Pipe Line Co., 458 U.S. 50, 102 S.Ct. 2858, 73 L.Ed.2d 598 (1982)). The appellees urge us to adopt a “but-for” test to determine whether a proceeding is core or noncore. According to this logic, if a cause of action would not have arisen “but for” the bankruptcy case, it is within the bankruptcy court’s jurisdiction. Because the antitrust action could not have arisen without the Trustee’s sale of the cobalt-60, the appellees maintain, the antitrust claims constitute core matt 3 (5th Cir.1990) (<HOLDING>). CONCLUSION The district court erred in ruling
holding that action for rico violations against shareholders officers and directors of corporations that had filed for chapter 11 reorganization and had completed confirmation proceedings was not a core proceeding recognizing privilege for corporate officers directors and shareholders to influence the actions of their corporation holding that remedies provided in the bankruptcy code for enforcing a chapter 11 plan of reorganization are not exclusive recognizing a cause of action against a corporations directors brought by a creditor for the fraudulent misrepresentation of the corporations financial condition holding a shareholders cause of action accrued for statute of limitations purposes when shareholders and directors of a company asserted a right to stock which was hostile to the plaintiffs claim to the stock