(Repeats to separate story from related Dec. 15 news alert) * Competing plan may be filed this week - source * Paulson, Calpers have opposed Lehman's plan * Estimated $57.5 bln assets to be distributed NEW YORK, Dec 14 (Reuters) - Creditors of Lehman Brothers Holdings Inc, including hedge fund Paulson & Co, may file a competing reorganization plan for distributing the bank's assets, a person familiar with the matter said. The plan, which may be filed this week, would come more than two years after Lehman filed the largest U.S. bankruptcy ever and would vie against Lehman's own reorganization proposal filed in March. Paulson & Co, led by billionaire John Paulson, and other creditors including the California Public Employees' Retirement System, or Calpers, have opposed the company's plan, saying it would treat large bank creditors better than other creditors and spur litigation. Calpers is the largest U.S. pension fund. Paulson & Co declined ...