Exhibit 99(b)



                                    TXU CORP.
                       Certificate Pursuant to Section 906
                         of Sarbanes - Oxley Act of 2002
                      CERTIFICATION OF ASSISTANT SECRETARY
                                       AND
                      SECRETARY, TXU THRIFT PLAN COMMITTEE


     The  undersigned,  Diane J. Kubin,  Assistant  Secretary of TXU Corp.,  and
Secretary of the TXU Thrift Plan (the  "Plan")  Committee,  DOES HEREBY  CERTIFY
that:

  1. The Annual Report on Form 11-K for the year ended December 31, 2002
     (the "Report") of the Plan fully complies with the requirements of
     section 13(a) or 15(d) of the Securities Exchange Act of 1934, as
     amended; and

  2. Information contained in the Report fairly presents, in all material
     respects, the financial condition and results of operation of the Plan.

     IN WITNESS WHEREOF, the undersigned has caused this instrument to be
executed this 15th day of July, 2003.





                                   /s/  Diane J. Kubin
                                 -------------------------------------------
                                 Name:  Diane J. Kubin
                                 Title: Assistant Secretary
                                        Secretary, TXU Thrift Plan Committee











A signed original of this written statement required by Section 906 has been
provided to TXU Corp. and will be retained by TXU Corp. and furnished to the
Securities and Exchange Commission or its staff upon request.