Exhibit 4 (b) March 8, 2002 Securities and Exchange Commission Judiciary Plaza 450 Fifth Street, N.W. Washington, D.C. 20549 Re: TXU US Holdings Company 2001 Annual Report on Form 10-K Gentlemen: Pursuant to the exemption afforded by Item 601(b) (4) (iii) (A) of Regulation S-K, TXU US Holdings Company (the Company) is not filing as exhibits to its Annual Report on Form 10-K for 2001 instruments with respect to its long-term debt, consisting of pollution control revenue bonds as the aggregate amounts represented thereby do not exceed 10% of the total assets of the Company and its subsidiaries on a consolidated basis. Reference is made to Note 7 to Consolidated Financial Statements (included in Appendix A of the Company's Annual Report on Form 10-K for 2001). The Company agrees to furnish a copy of the above instruments to the Securities and Exchange Commission upon request. Sincerely, /s/ Biggs C. Porter ------------------------------------------------------- Biggs C. Porter Controller and Principal Accounting Officer