Nicor Inc.
                                                                      Form 10-Q
                                                                   Exhibit 32.1

                                  CERTIFICATION

      Pursuant to 18 U.S.C. Section 1350, as created by Section 906 of the
Sarbanes-Oxley Act of 2002, the undersigned officer of Nicor Inc. (the
"Company") hereby certifies, to such officer's knowledge, that:

      (i) the accompanying Quarterly Report on Form 10-Q of the Company for the
   quarterly period ended September 30, 2003 (the "Report") fully complies with
   the requirements of Section 13(a) or Section 15(d), as applicable, of the
   Securities Exchange Act of 1934, as amended; and

      (ii) the information contained in the Report fairly presents, in all
   material respects, the financial condition and results of operations of the
   Company.


   Dated:  November 4, 2003               /s/ THOMAS L. FISHER
          --------------------            -------------------------
                                          Thomas L. Fisher
                                          Chairman and Chief Executive Officer





                                                                      Nicor Inc.
                                                                      Form 10-Q
                                                                   Exhibit 32.2

                                  CERTIFICATION

      Pursuant to 18 U.S.C. Section 1350, as created by Section 906 of the
Sarbanes-Oxley Act of 2002, the undersigned officer of Nicor Inc. (the
"Company") hereby certifies, to such officer's knowledge, that:

      (i) the accompanying Quarterly Report on Form 10-Q of the Company for the
   quarterly period ended September 30, 2003 (the "Report") fully complies with
   the requirements of Section 13(a) or Section 15(d), as applicable, of the
   Securities Exchange Act of 1934, as amended; and

      (ii) the information contained in the Report fairly presents, in all
   material respects, the financial condition and results of operations of the
   Company.


Dated:  November 4, 2003                   /s/ KATHLEEN L. HALLORAN
       ------------------                  --------------------------
                                           Kathleen L. Halloran
                                           Executive Vice President
                                           Finance and Administration