Exhibit 99-4

               Certificate Pursuant to Section 1350 of Chapter 63
                         of Title 18 United States Code
              -----------------------------------------------------


         The undersigned  officer hereby certifies,  as to the Amended Quarterly
Report on Form 10-Q/A of Exelon Generation Company, LLC for the quarterly period
ended June 30, 2002, that (i) the report fully complies with the requirements of
section  13(a) or 15(d) of the  Securities  Exchange  Act of 1934,  and (ii) the
information  contained in the report fairly presents,  in all material respects,
the financial  condition and results of operations of Exelon Generation Company,
LLC.



Date:  October 30, 2002                     /s/ Ruth Ann M. Gillis
                                            ---------------------------
                                            Ruth Ann M. Gillis
                                            Senior Vice President and
                                            Chief Financial Officer
                                            Exelon Generation Company, LLC