<PAGE>

                                   Form 10-Q

                      SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, D.C. 20549


               QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d)
     [ X ]         OF THE SECURITIES EXCHANGE ACT OF 1934
               For the quarterly period ended September 30, 1999

                                      OR

               TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d)
     [   ]         OF THE SECURITIES EXCHANGE ACT OF 1934
            For the transition period from __________ to __________

                         Commission file number 1-5666
                         -----------------------------


                            UNION TANK CAR COMPANY
            (Exact name of registrant as specified in its charter)


            Delaware                                  36-3104688
            --------                                  ----------
      (State or other jurisdiction of              (I.R.S. Employer
      incorporation or organization)             Identification Number)


              225 West Washington Street, Chicago, Illinois 60606
              ---------------------------------------------------
                   (Address of principal executive offices)

      Registrant's telephone number, including area code:  (312) 372-9500

Indicate by check mark whether the registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the preceding 12 months (or for such shorter period that the registrant was
required to file such reports), and (2) has been subject to such filing
requirements for the past 90 days.

                  Yes    X                 No __________
                      --------

There is no voting stock held by non-affiliates of the registrant. This report
is being filed by the registrant as a result of undertakings made pursuant to
Section 15(d) of the Securities Exchange Act of 1934.

Included in this filing are 11 pages, sequentially numbered in the bottom center
of each page.

                                      -1-
<PAGE>

                    UNION TANK CAR COMPANY AND SUBSIDIARIES
                                   FORM 10-Q
                                     INDEX

<TABLE>
<CAPTION>
                                                                                                     Page
                                                                                                     ----
<S>                                                                                                 <C>
Part I.  Financial Information

          Item 1.  Financial Statements

                   Condensed consolidated statement of income -
                    three and nine month periods ended
                    September 30, 1999 and 1998                                                         3

                   Condensed consolidated balance sheet -
                    September 30, 1999 and December 31, 1998                                            4

                   Condensed consolidated statement of cash flows -
                    nine months ended September 30, 1999 and 1998                                       5

                   Notes to condensed consolidated financial statements                             6 - 7

          Item 2.  Management's Discussion and Analysis
                   of Financial Condition and Results of Operations                                 8 - 9

          Item 3.  Quantitative and Qualitative Disclosures About Market Risk                          10


Part II.  Other Information

          Item 1.  Legal Proceedings                                                                   10

          Item 6.  Exhibits and Reports on Form 8-K                                                    10

Signatures                                                                                             11
</TABLE>

                                      -2-
<PAGE>

                       PART I.    FINANCIAL INFORMATION


ITEM 1.  FINANCIAL STATEMENTS

                    UNION TANK CAR COMPANY AND SUBSIDIARIES
                  CONDENSED CONSOLIDATED STATEMENT OF INCOME
                            (Dollars in Thousands)
                                  (Unaudited)


<TABLE>
<CAPTION>
                                                    Three Months Ended                            Nine Months Ended
                                                       September 30,                                 September 30,
                                          --------------------------------------        --------------------------------------
                                                 1999                 1998                     1999                 1998
                                          -----------------    -----------------        -----------------    -----------------
<S>                                       <C>                  <C>                      <C>                  <C>
Revenues
   Services (leasing and other)           $         156,289    $         144,496        $         466,305    $         430,367
   Net sales                                         83,682               75,114                  257,500              199,702
                                          -----------------    -----------------        -----------------    -----------------

                                                    239,971              219,610                  723,805              630,069
Other income                                          7,346                5,398                   19,498               21,354
                                          -----------------    -----------------        -----------------    -----------------

                                                    247,317              225,008                  743,303              651,423
Costs and expenses
   Cost of services                                  91,440               80,132                  271,749              239,271
   Cost of sales                                     74,453               64,157                  224,867              169,589
   General and administrative                        19,041               15,965                   55,791               46,111
   Interest                                          19,060               18,068                   54,433               54,431
                                          -----------------    -----------------        -----------------    -----------------
                                                    203,994              178,322                  606,840              509,402
                                          -----------------    -----------------        -----------------    -----------------

Income before income taxes                           43,323               46,686                  136,463              142,021

Provision for income taxes
   Current                                            8,997               15,215                   35,540               44,620
   Deferred                                           6,756                4,544                   16,023               12,575
                                          -----------------    -----------------        -----------------    -----------------
                                                     15,753               19,759                   51,563               57,195
                                          -----------------    -----------------        -----------------    -----------------
Net income                                $          27,570    $          26,927        $          84,900    $          84,826
                                          =================    =================        =================    =================
</TABLE>

           See notes to condensed consolidated financial statements.

                                      -3-
<PAGE>

                    UNION TANK CAR COMPANY AND SUBSIDIARIES
                     CONDENSED CONSOLIDATED BALANCE SHEET
                            (Dollars in Thousands)



<TABLE>
<CAPTION>
                                                                        September 30,                December 31,
                                                                            1999                         1998
                                                                     -------------------            -----------------
                                                                        (Unaudited)
<S>                                                                  <C>                            <C>
Assets
------

Cash and cash equivalents                                            $            70,698            $          58,423
Accounts receivable, primarily due within one year                                99,388                       82,729
Inventories                                                                       87,148                       90,123
Prepaid expenses and deferred charges                                             11,028                       11,411
Advances to parent company,
    principally at LIBOR plus 1%                                                 203,959                      130,940
Railcar lease fleet, net                                                       1,627,158                    1,575,014
Fixed assets, net                                                                189,518                      177,055
Investment in aircraft direct financing lease                                     33,598                       32,629
Other assets                                                                      50,487                       53,851
                                                                     -------------------            -----------------

      Total assets                                                   $         2,372,982            $       2,212,175
                                                                     ===================            =================


Liabilities, Deferred Items and Stockholder's Equity
----------------------------------------------------

Accounts payable                                                     $            20,953            $          20,082
Accrued liabilities                                                              234,272                      252,897
Borrowed debt, including $44,808 due within
    one year ($46,951 at December 31, 1998)                                    1,002,015                      868,421
                                                                     -------------------            -----------------
                                                                               1,257,240                    1,141,400


Deferred income taxes and investment tax credits                                 456,760                      437,693


Stockholder's equity
  Common stock and additional capital                                            113,035                      113,035
  Retained earnings                                                              545,947                      520,047
                                                                     -------------------            -----------------

    Total stockholder's equity                                                   658,982                      633,082
                                                                     -------------------            -----------------

      Total liabilities, deferred items and                          $         2,372,982            $       2,212,175
               stockholder's equity                                  ===================            =================
</TABLE>

           See notes to condensed consolidated financial statements.

                                      -4-
<PAGE>

                    UNION TANK CAR COMPANY AND SUBSIDIARIES
                CONDENSED CONSOLIDATED STATEMENT OF CASH FLOWS
                            (Dollars in Thousands)
                                  (Unaudited)

<TABLE>
<CAPTION>
                                                                                              Nine Months Ended
                                                                                                September 30,
                                                                                ---------------------------------------------
                                                                                       1999                       1998
                                                                                ------------------         ------------------
<S>                                                                             <C>                        <C>
Cash flows from operating activities:
  Net income                                                                    $           84,900         $           84,826
  Adjustments to reconcile net income to net cash
    provided by operating activities:
       Depreciation and amortization                                                        97,684                     90,780
       Deferred taxes                                                                       16,023                     12,575
       Gain on disposition of railcars and other fixed assets                               (4,777)                    (1,752)
       Other non-cash income and expenses                                                    1,463                      1,308
       Changes in assets and liabilities:
         Accounts receivable                                                               (13,704)                   (18,558)
         Inventories                                                                         4,321                    (15,835)
         Prepaid expenses and deferred charges                                                 573                        695
         Accounts payable and accrued expenses                                             (22,029)                    (9,365)
                                                                                ------------------         ------------------
Net cash provided by operating activities                                                  164,454                    144,674

Cash flows from investing activities:
  Construction and purchase of railcars and other fixed assets                            (155,145)                  (189,115)
  (Increase) decrease in advance to parent                                                 (81,059)                    20,082
  (Increase) in other assets                                                                  (357)                         -
  Purchases of businesses, net of cash acquired                                            (11,764)                   (21,989)
  Proceeds from disposals of railcars and other fixed assets                                 9,413                     14,430
                                                                                ------------------         ------------------
Net cash used in investing activities                                                     (238,912)                  (176,592)

Cash flows from financing activities:
  Proceeds from issuance of borrowed debt                                                  175,000                     80,550
  Proceeds from sale-leaseback transactions                                                 13,200                    130,018
  Principal payments of borrowed debt                                                      (44,773)                  (155,970)
  Cash dividends                                                                           (59,000)                   (59,000)
                                                                                ------------------         ------------------
Net cash provided (used in) by financing activities                                         84,427                     (4,402)

Effect of exchange rates on cash and cash equivalents                                        2,306                     (6,506)
                                                                                ------------------         ------------------
Net increase (decrease) in cash and cash equivalents                                        12,275                    (42,826)

Cash and cash equivalents at beginning of year                                              58,423                     99,709
                                                                                ------------------         ------------------
Cash and cash equivalents at end of period                                      $           70,698         $           56,883
                                                                                ==================         ==================
Cash paid during the period for:
  Interest (net of amount capitalized)                                          $           56,984         $           56,131
  Income taxes                                                                              42,125                     42,823
</TABLE>

           See notes to condensed consolidated financial statements.

                                      -5-
<PAGE>

                    UNION TANK CAR COMPANY AND SUBSIDIARIES
             NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS
                            (Dollars in Thousands)
                                  (Unaudited)


1.  UNION TANK CAR COMPANY (the "Company") is a wholly-owned subsidiary of
    Marmon Industrial LLC ("Marmon Industrial"). Marmon Industrial is a wholly-
    owned subsidiary of Marmon Holdings, Inc. ("Marmon Holdings"), substantially
    all of the stock of which is owned, directly or indirectly, by trusts for
    the benefit of certain members of the Pritzker family. As used herein,
    "Pritzker family" refers to the lineal descendants of Nicholas J. Pritzker,
    deceased.

2.  The accompanying unaudited condensed consolidated financial statements
    include all adjustments, consisting of normal recurring accruals, which the
    Company considers necessary for a fair presentation. These interim financial
    statements do not include all disclosures normally provided in annual
    financial statements. Accordingly, they should be read in conjunction with
    the consolidated financial statements and notes thereto in the Company's
    1998 Annual Report on Form 10-K.

    Certain prior year amounts have been reclassified to conform to the current
    year presentation.

    The 1999 interim results presented herein are not necessarily indicative of
    the results of operations for the full year 1999.

3.  As more fully described in the Company's 1998 Annual Report on Form 10-K,
    under an arrangement with Marmon Industrial, the Company is included in the
    consolidated federal income tax return of Marmon Holdings. As a member of a
    consolidated federal income tax group, the Company is contingently liable
    for the federal income taxes of the other members of the group.

4.  The Company and its subsidiaries have been named as defendants in a number
    of lawsuits, and certain claims are pending. The Company has accrued what it
    reasonably expects to pay in resolution of these matters and, in the opinion
    of management, their ultimate resolution will not have a material effect on
    the Company's consolidated financial position or results of operations.

5.  Foreign currency translation adjustments and transaction gains and losses
    are assumed by the Company's parent. For the nine months ended September 30,
    1999 and 1998, Marmon Industrial absorbed a loss of $470 and a gain of
    $3,508, respectively.

6.  The Company's foreign subsidiaries periodically enter into foreign currency
    forward contracts to hedge against U.S. dollar exposures. Foreign currency
    forward contracts, all with initial maturities of less than one year,
    amounted to $8,450 at September 30, 1999 and $3,365 at December 31, 1998.

                                      -6-
<PAGE>

7. Segment Information

<TABLE>
<CAPTION>
                                                                                                     Consolidated
                                                    Railcar                 All Other                   Totals
                                               ---------------         ----------------            ---------------
                                                                       (Dollars in Millions)
<S>                                            <C>                     <C>                         <C>
Three months ended September 30, 1999
-------------------------------------
Revenues from external customers                      $  191.2                 $   48.8                   $  240.0
Income (loss) before income taxes                         46.4                     (3.1)                      43.3

Three months ended September 30, 1998
-------------------------------------
Revenues from external customers                      $  182.6                 $   37.0                   $  219.6
Income (loss) before income taxes                         54.2                     (7.5)                      46.7

Nine months ended September 30, 1999
------------------------------------
Revenues from external customers                      $  574.6                 $  149.2                   $  723.8
Income (loss) before income taxes                        141.5                     (5.0)                     136.5

Nine months ended September 30, 1998
------------------------------------
Revenues from external customers                      $  523.4                 $  106.7                   $  630.1
Income (loss) before income taxes                        147.0                     (5.0)                     142.0
</TABLE>

8. Summarized Financial Information of Procor Limited

   Summarized consolidated financial information for the Company's wholly-owned
   subsidiary, Procor Limited, in thousands of U.S. dollars, is as follows:

<TABLE>
<CAPTION>
                                                         September 30,                December 31,
                                                             1999                         1998
                                                    ---------------------          -------------------
<S>                                                 <C>                            <C>
Balance Sheet:
  Railcar lease fleet, net                                       $161,784                     $165,270
  All other assets                                                181,395                      170,214
  Borrowed debt                                                    89,813                       94,409
  All other liabilities                                           105,207                      109,431
</TABLE>


<TABLE>
<CAPTION>
                                                   Three Months Ended                               Nine Months Ended
                                                     September 30,                                    September 30,
                                            ------------------------------------           -------------------------------------
                                               1999                  1998                     1999                 1998
                                            --------------       ---------------           --------------       ----------------
<S>                                         <C>                  <C>                       <C>                  <C>
Statement of Income:
    Services and net sales                        $ 27,828              $ 29,111               $ 87,283                 $ 83,667
    Gross profit                                     8,661                10,255                 25,928                   27,721
    Net income                                       3,754                 6,648                 10,881                   15,239
</TABLE>

                                      -7-
<PAGE>

ITEM 2.  MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION
         AND RESULTS OF OPERATIONS

Results of Operations
---------------------
3rd Quarter 1999 versus 1998
----------------------------

Service revenues increased $11.8 million primarily due to the effects of
railcars added to the lease fleet and the acquisition in the fourth quarter of
1998 of a company which provides contract switching services.

Sales revenues increased $8.6 million primarily due to increased sales of
railcars and sales of mobile railcar moving vehicles by a company which was
acquired in the fourth quarter of 1998.

General and administrative expenses increased $3.1 million primarily due to the
acquisition of businesses in 1998.

Nine Months 1999 versus 1998
----------------------------

Service revenues increased $35.9 million primarily due to the effects of
railcars added to the lease fleet and the acquisition in the fourth quarter of
1998 of a company which provides contract switching services.

Sales revenues increased $57.8 million primarily due to increased sales of
railcars and sales of mobile railcar moving vehicles by a company which was
acquired in the fourth quarter of 1998.

General and administrative expenses increased $9.7 million primarily due to the
acquisition of businesses in 1998.


Financial Condition
-------------------
1999 versus 1998
----------------

Operating activities provided $164.5 million of cash. These funds, along with
the proceeds from the issuance of debt and sale-leaseback transactions were used
to provide for railcar additions, advance funds to parent, pay dividends to the
Company's stockholder, service borrowed debt obligations, and fund the
acquisition of businesses.

Management expects future cash to be provided from operating activities, long-
term financings and repayment of funds previously advanced to parent will be
adequate to provide for continued expansion of the Company's business and enable
it to meet its debt service obligations.


Year 2000
---------

Because of the potential importance to the Company of Year 2000 questions, the
Company has established a Year 2000 program to determine the Company's state of
readiness and the costs it anticipates it will have to incur in light of any
possible problems and to remediate any problems discovered. The Company's Year
2000 assessment indicated that the Company's accounting, invoicing, general
business and fleet management systems would be affected by Year 2000 problems.
As of September 30, 1999, the Company has completed the necessary corrective
work on its accounting, invoicing, general business and fleet management systems
that would be affected by Year 2000 problems. The Company's testing of the
systems was successfully completed on October 1, 1999.

                                      -8-
<PAGE>

The Company does not believe its main products (i.e., tank cars and other
railcars) have any material Year 2000 exposures.  Similarly, no significant
problems have been identified in connection with the Company's production
machinery and equipment.

The Company is using both in-house resources and outside consultants to
implement the necessary changes required by its Year 2000 program.  The total
cost of the program is estimated to be $5.5 million, which has been and will
continue to be funded from operating cash flow.  Through September 30, 1999, the
Company had spent approximately $5.2 million related to its Year 2000 program,
of which $4.8 million has been expensed and $0.4 million has been capitalized.
The remaining cost, estimated to be $0.3 million, is expected to be expensed.

For further discussion of the Company's Year 2000 program and risks related
thereto, see "Management's Discussion and Analysis of Financial Condition and
Results of Operations" in the Company's Annual Report on Form 10-K for the year
ended December 31, 1998.

                                      -9-
<PAGE>

ITEM 3.  QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

At September 30, 1999, there has been no significant change to the Company's
exposure to and management of market risk since December 31, 1998.


                          PART II.  OTHER INFORMATION


Item 1.   Legal Proceedings

          Reference is made to "Business - Environmental Matters" in the
          Company's Annual Report on Form 10-K for the year ended December 31,
          1998 for a description of certain environmental matters.


Item 6.   Exhibits and Reports on Form 8-K

     b.   No Report on Form 8-K was filed during the quarter ended September 30,
          1999.

                                      -10-
<PAGE>

                                  SIGNATURES



Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned thereunto duly authorized.



                                      UNION TANK CAR COMPANY

                                      REGISTRANT



Dated:  November 3, 1999              /s/ R.C. Gluth
                                      -------------------------------
                                          R.C. Gluth
                                      Executive Vice President,
                                      Director and Treasurer
                                      (principal financial officer
                                      and principal accounting
                                      officer)

                                      -11-