FILED PURSUANT TO RULE 424(b)(3)
                                                     REGISTRATION NO. 333-110451
                                                                   333-110451-01


PROSPECTUS SUPPLEMENT NO. 2


                                  $125,000,000

                                GATX CORPORATION

                      5% SENIOR CONVERTIBLE NOTES DUE 2023
                     FULLY AND UNCONDITIONALLY GUARANTEED BY

                           GATX FINANCIAL CORPORATION

                           AND SHARES OF COMMON STOCK
                      ISSUABLE UPON CONVERSION OF THE NOTES

         This prospectus supplement supplements the prospectus dated January 20,
2004 of GATX Corporation and GATX Financial Corporation, as supplemented by
prospectus supplement No. 1 dated January 30, 2004, relating to the sale by
certain holders of our 5% Senior Convertible Notes due 2023 and the shares of
our common stock issuable upon conversion of the notes. You should read this
prospectus supplement in conjunction with the prospectus. This prospectus
supplement is qualified by reference to the prospectus except to the extent that
the information in this prospectus supplement supersedes the information
contained in the prospectus. Capitalized terms used in this prospectus
supplement and not otherwise defined herein have the meanings specified in the
prospectus.

         The table of Selling Holders contained in the prospectus is hereby
amended to add the entities who are named below as Selling Holders:




                                                                     PRINCIPAL AMOUNT OF
                                                                     NOTES BENEFICIALLY        NUMBER OF SHARES
                                                                         OWNED THAT            OF COMMON STOCK
NAME OF SELLING HOLDER                                                   MAY BE SOLD           THAT MAY BE SOLD
- ----------------------                                              --------------------       ----------------
                                                                                         
JP Morgan Securities Inc.  .....................................    $      3,065,000               129,371

         In addition, the following line item in the table of Selling Holders
contained in the prospectus is hereby amended as follows:






                                                                     PRINCIPAL AMOUNT OF
                                                                     NOTES BENEFICIALLY        NUMBER OF SHARES
                                                                         OWNED THAT            OF COMMON STOCK
NAME OF SELLING HOLDER                                                   MAY BE SOLD           THAT MAY BE SOLD
- ----------------------                                              --------------------       ----------------
                                                                                         
Citigroup Global Markets Inc.(2)  ..............................    $      8,660,000               365,532


- -------------



(2) Citigroup Global Markets Inc. was among the initial purchasers of the notes.

         INVESTING IN THE NOTES AND OUR COMMON STOCK INVOLVES RISKS. SEE "RISK
FACTORS" BEGINNING ON PAGE 5 OF THE PROSPECTUS.

                                 -------------

         NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES
COMMISSION HAS APPROVED OR DISAPPROVED OF THESE SECURITIES OR PASSED UPON THE
ACCURACY OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS A
CRIMINAL OFFENSE.

                                 -------------

            The date of this prospectus supplement is March 15, 2004