WILMINGTON, Del. - A creditor in the Chapter 11 bankruptcy of alternative energy company A123 Systems Inc. on Nov. 26 filed a brief in the U.S. Bankruptcy Court for the District of Delaware objecting to the company's plan to reject various contracts on grounds that doing so would jeopardize the creditor's ability to continue operating (In Re: A123 Systems Inc., No. 12-12859, Chapter 11, D. Del. Bkcy.).