Exhibit 16 Office of the Chief Accountant SECPS Letter File Securities and Exchange Commission Mail Stop 11-3 450 Fifth Street, N.W. Washington, D.C. 20549 November 29, 2000 Dear Sir or Madam: We have read the paragraphs under Item 4 included in the Form 8-K dated November 29, 2000 of Commonwealth Edison Company to be filed with the Securities and Exchange Commission and are in agreement with the statements contained therein in response to Item 304(a) of Regulation S-K. Very truly yours, Arthur Andersen LLP Copy to: Ms. Ruth Ann Gillis 	 Chief Financial Officer Exelon